Condition Analysis
AI-powered assessment using site data and 14-day weather history
Five consecutive dry days following light rain (4.5mm on Aug 9), with warm temperatures peaking at 29°C yesterday and moderate winds, suggest the rock should be approaching climbable condition. However, Corby's Crag's sheltered, below-road-level position and its notably porous, friable sandstone mean residual internal moisture and runoff seepage cannot be ruled out without an on-site check.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Corby's below-road-level position channels runoff from the road and surrounding land onto the rock face, meaning it can be wet even when nearby crags are fully dry — check the crag top and upper face for damp patches before committing.
- The rock here is more friable and porous than typical Northumberland Fell Sandstone; after recent rain it can develop 'scrittle' (loose surface grit) on holds even when the surface looks dry, so test holds carefully.
- The heavy 14.7mm rain on July 26 followed by repeated light showers through early August means the rock has had limited opportunity for deep drying despite the recent 5-day dry spell — internal moisture may linger in this sheltered setting.
- The sheltered aspect traps warm air on sunny days and can feel deceptively pleasant, but this same lack of airflow significantly slows evaporation from the rock mass — wind exposure matters more than temperature here.
Warnings
2
- Do not climb if the crag top or base soil is damp — this indicates internal moisture remains despite a dry surface.
- Rain is forecast from Aug 17 onwards; conditions will deteriorate significantly and the rock will need a fresh extended drying period after that.
Reasoning
The last significant rain was 4.5mm on Aug 9, five days ago, but the preceding weeks saw repeated wetting events (14.7mm on July 26, 5.5mm on Aug 4, 2.0mm on Aug 6) that kept the porous rock periodically saturated, and the sheltered position limits deep drying.
Five dry days with warm temperatures (up to 29°C) and moderate SW winds provide reasonable surface drying, but the sheltered, below-road-level aspect reduces effective wind exposure and the NW-facing sections will have dried more slowly than the south-facing ones.
The friable, high-porosity Fell Sandstone at Corby's is particularly vulnerable to hold breakage if internal moisture remains — the repeated wetting cycles over the past three weeks increase the risk of weakened grain bonds even if the surface appears dry.
Mid-summer conditions are broadly favourable with long days and warm temperatures aiding evaporation, though humidity has averaged 72% over the past week which is moderate rather than ideal for rapid drying.
Contributing Factors
6
Five full days without measurable rain, including two very warm days (24°C and 29°C), have allowed significant surface drying.
The crag's sheltered, recessed position limits wind-driven evaporation and channels road runoff onto the face, substantially slowing drying compared to exposed crags.
Multiple rain events over the past three weeks (14.7mm, 5.5mm, 2.0mm, 4.5mm) have kept the porous rock periodically saturated, limiting deep drying between events.
Temperatures reaching 24–29°C over the past two days significantly accelerate evaporation from the rock surface and shallow interior.
Average humidity of 72% over the past week is neither especially high nor low — adequate for drying but not optimal.
Forecast rain totalling over 15mm from Aug 17–19 will re-saturate the rock, closing the current drying window within two days.
Recommendations
3
- Visit today or tomorrow (Aug 14–15) for the best chance of acceptable conditions before forecast rain arrives on Aug 17; visually inspect the crag top and upper face for dampness before climbing.
- Prioritise the south-facing sections which will have dried faster, and avoid any routes showing dark patches, seepage lines, or surface grit ('scrittle') on holds.
- Do not top-rope on this soft Fell Sandstone — use lead or bottom-rope alternatives to protect the fragile crag edge and route surfaces.
Previous Analyses
Marginal — Assess Conditions
70%
2 days ago
Four full dry days since the last meaningful rain (4.5mm on Aug 9), with today reaching 27°C and low humidity — conditions are promising, especially on south-facing sections. However, Corby's Crag's sheltered, below-road-level position and its known tendency to channel runoff mean a visual check is essential before committing to climb.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Corby's Crag sits below road level and channels runoff from above onto the rock face, meaning it can remain wet even when nearby crags have dried out.
- The rock here is notably more friable and porous than other Northumberland Fell Sandstone, and develops 'scrittle' (loose surface grit) after rain that persists even when the surface looks dry — feel holds carefully before pulling on them.
- The sheltered position limits wind-assisted drying despite moderate regional winds; the south-facing sections will have benefited most from today's exceptional warmth and sunshine.
- The 14.7mm event on July 26 was heavy and, combined with repeated smaller showers since (Aug 3–6, Aug 9), the rock has had a cumulative moisture load this summer — deep internal moisture may still be present in NW-facing sections.
Warnings
2
- Do not top-rope on this soft Fell Sandstone — the rock is particularly susceptible to rope erosion damage.
- NW-facing sections may still harbour internal moisture despite surface dryness; exercise extra caution on these aspects.
Reasoning
The last significant rain was 4.5mm on Aug 9, with four consecutive dry days since, but the cumulative pattern of repeated showers through late July and early August means the porous Fell Sandstone — especially in this sheltered, below-road setting — may retain internal moisture despite surface drying.
Today's exceptional warmth (27°C) and low humidity (49–55% midday) with a southerly breeze will have substantially aided drying on south-facing sections, but the crag's sheltered position reduces effective wind exposure, and NW-facing rock will have received far less direct solar heating.
The known friability and high porosity of this particular outcrop, combined with repeated wetting events over the past three weeks, mean some residual internal moisture is plausible and hold breakage risk is elevated on any sections that haven't fully dried.
Mid-summer conditions are generally favourable with long days and warm temperatures, and today's 27°C peak is well above average for Northumberland — this is close to optimal drying weather for the season.
Contributing Factors
6
Four full days without meaningful precipitation since the 4.5mm on Aug 9 meets the minimum community guideline of two dry days, with a comfortable margin.
Today's 27°C maximum with humidity dropping to ~50% at midday provides near-optimal evaporative drying conditions for Northumberland.
The crag's sheltered, sunken position significantly reduces wind-assisted drying and channels road-level runoff onto the face, meaning regional drying conditions overestimate actual crag drying.
Repeated rainfall events (14.7mm on Jul 26, plus showers on Aug 3–6 and Aug 9, totalling 30mm in 28 days) have kept the porous rock periodically saturated, and deep internal moisture may persist.
South-facing sections have received direct sun and the prevailing southerly winds today, likely drying well, but NW-facing sections will be significantly slower to dry.
Wind speeds of 14–23 km/h from varying directions over the past four days have aided surface evaporation, though the sheltered setting reduces their effective reach at crag level.
Recommendations
3
- Check the crag top and base for dampness before committing — if the ground at the base is moist or the top is seeping, the rock interior is still wet.
- Prioritise south-facing routes which will have benefited most from today's warmth; avoid NW-facing sections unless they are visibly and tactilely bone-dry.
- Feel holds carefully for 'scrittle' (loose surface grit) before weighting them — this crag is known for retaining a deceptive gritty layer even after the surface appears dry.
Do Not Climb
45%
3 days ago
Despite a warm day today, Corby's Crag has received repeated light-to-moderate rainfall over the past week (4.5mm on Aug 9, 2.0mm on Aug 6, 5.5mm on Aug 4) with only short dry spells between showers, and its sheltered below-road-level position means internal moisture is almost certainly still present. The rock's known friability and tendency to develop 'scrittle' after rain makes climbing inadvisable until a longer sustained dry spell occurs.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Corby's below-road-level position channels runoff from the road and hillside above onto the rock face, meaning the crag can be wetter than surrounding areas even after modest rainfall.
- The rock here is notably more friable and porous than typical Northumberland Fell Sandstone, and develops loose 'scrittle' on holds after rain that persists well beyond surface drying — a long sustained dry spell is needed to clear this.
- The sheltered setting with minimal air movement significantly retards drying; the 14–24 km/h winds recorded at weather stations will be greatly attenuated at the crag itself.
- The south-facing sections will be drying faster today in the warm conditions (up to 25°C), but the NW-facing sections will lag considerably and remain the last to dry.
Warnings
2
- Climbing on wet or damp Fell Sandstone causes permanent, irreversible damage to holds — this crag is already noted as more friable than typical Northumberland sandstone.
- Surface-dry appearance is unreliable at Corby's; the 'scrittle' phenomenon indicates internal moisture even when the face looks climbable.
Reasoning
With 4.5mm on Aug 9, light drizzle on Aug 10–12, and only two genuinely dry days since, internal moisture levels in this highly porous and friable sandstone are likely still elevated, particularly on the NW-facing sections and at the base where runoff accumulates.
Although today is warm (up to 25°C) with moderate humidity (~47–66% in the afternoon), the sheltered position greatly reduces effective wind speed at the rock face, and the cumulative pattern of repeated showers over the past two weeks (30.3mm in 28 days with no dry spell longer than 4 days) means deep moisture has never fully cleared.
The known 'scrittle' problem at Corby's — loose grit developing on holds after rain — indicates active grain loosening, and climbing before the rock is thoroughly dry risks accelerating permanent hold degradation on this already friable sandstone.
Mid-summer temperatures are helpful for drying, but the pattern of frequent Atlantic showers reaching Northumberland has prevented the sustained dry period this crag specifically requires.
Contributing Factors
6
Rainfall on Aug 4 (5.5mm), Aug 5 (0.5mm), Aug 6 (2.0mm), Aug 9 (4.5mm), and trace amounts on Aug 3, 10, and 12 means the rock has been repeatedly re-wetted with no sustained drying window.
The crag's sheltered setting below road level traps moisture and blocks wind, dramatically slowing drying compared to exposed crags, and channels runoff from above onto the face.
Today's peak of ~25°C with humidity dropping to 47% in the afternoon provides good surface evaporation potential, though this is attenuated by the sheltered position.
Corby's notably porous and friable sandstone develops loose 'scrittle' on holds after wetting, requiring a longer drying period than typical Fell Sandstone before conditions are truly safe.
The NW-facing sections receive little direct sun and will dry far more slowly than the south-facing areas, creating a false sense of dryness if only the sunny sections are checked.
Light precipitation is forecast for Aug 13 (0.4mm) and Aug 14 (0.9mm), followed by heavier rain on Aug 16 (5.1mm) and Aug 17 (6.2mm), preventing a sustained drying window this week.
Recommendations
3
- Do not climb today or in the next couple of days — the repeated wetting pattern and Corby's slow-drying characteristics mean internal moisture is almost certainly still present.
- If visiting, check the crag top and base for dampness before committing; if the ground at the base is moist or the crag top shows any seepage, the rock is too wet.
- Consider faster-drying alternatives such as whinstone crags (e.g. Crag Lough, Peel Crag on the Whin Sill) which are non-porous and dry quickly.
Do Not Climb
45%
5 days ago
The last significant rain was 4.5mm on August 9th (yesterday), with additional rain of 5.5mm on August 4th and 2.0mm on August 6th — only one full dry day has elapsed since the most recent event. Given Corby's Crag's sheltered, below-road-level position and its notably friable, porous rock, one day of moderate drying with average humidity of 78% is insufficient to confidently clear internal moisture, and the 'scrittle' hazard is likely present.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Corby's Crag sits below road level, channelling runoff from the road and surrounding ground onto the rock face — this means the crag can be wetter than surrounding outcrops even after modest rain.
- The rock here is described as more friable and porous than typical Northumberland Fell Sandstone, and develops 'scrittle' (loose surface grit) after rain that persists even when the surface looks dry.
- The sheltered position suppresses wind-driven drying significantly; today's winds at the crag are likely well below the 13.7 km/h reported at station level.
- The south-facing sections will have benefited from any sun today, but the NW-facing sections will be substantially slower to dry and should be treated with extra caution.
Warnings
2
- Do not climb today — internal moisture from yesterday's 4.5mm rain is almost certainly still present, and the scrittle hazard poses both a safety risk and a rock damage risk.
- The below-road-level position means runoff may have added significantly more water to the rock than the 4.5mm recorded rainfall suggests.
Reasoning
With 4.5mm falling yesterday and cumulative rain of 12.5mm over the past seven days, the rock is very likely still holding significant internal moisture despite one dry day, especially given this crag's above-average porosity and below-road runoff.
Only one full dry day has passed since the last rain; the sheltered position limits effective wind exposure, average humidity has been ~78%, and temperatures around 15°C provide only moderate evaporative potential — far short of the sustained dry spell this crag requires.
The notably friable nature of Corby's rock means the scrittle hazard is very likely active after recent rain, and internal moisture weakening holds is a real concern even where the surface appears dry.
Mid-summer temperatures and daylight hours are favourable for drying, but the recent unsettled spell (repeated rain events through late July and early August) has kept the rock in a chronically damp state that will take more than one day to resolve.
Contributing Factors
7
4.5mm fell on August 9th — only one full dry day has elapsed, well short of the 48–72 hours needed for this porous, sheltered crag.
12.5mm over the past seven days across multiple events means the rock has had little chance to fully dry between wettings.
The sheltered, sunken setting drastically reduces wind-driven drying and channels road runoff onto the rock face.
Average humidity of 79% over the past week significantly slows evaporation from the rock surface and interior.
Mid-summer temperatures around 15–17°C provide moderate evaporative potential, better than spring or autumn conditions.
The next three days are forecast dry with rising temperatures to 28°C and dropping humidity to 63%, which will greatly improve drying.
This crag is specifically noted for developing loose surface grit after rain that persists well beyond the point where the surface appears dry.
Recommendations
3
- Wait at least until August 12th before visiting — the warm, drier conditions forecast from tomorrow will accelerate drying, and by Wednesday the rock should have had 3+ dry days with improving conditions.
- On arrival, check the crag top and base for dampness before committing; if the ground at the base is moist or the top is seeping, walk away.
- Favour the south-facing sections first when conditions allow, as these will dry faster than the NW-facing areas; avoid top-roping on this soft sandstone.
Do Not Climb
75%
5 days ago
Corby's Crag received 2.7mm of rain today on top of repeated recent showers (5.5mm on Aug 4, 2.0mm on Aug 6), and with zero consecutive dry days the rock will still be wet internally. The sheltered, below-road-level position and high recent humidity (~81% average) mean drying will be slow, and the particularly friable Fell Sandstone here needs an extended dry spell before it is safe to climb.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Corby's Crag sits below road level, channelling runoff from above onto the rock face — it can remain wet even when nearby crags have dried out.
- The rock here is notably more friable and porous than typical Northumberland sandstone, developing 'scrittle' (loose grit) on holds even after the surface appears dry — this requires a prolonged dry, windy spell to clear.
- The sheltered position traps still, humid air that significantly slows evaporation, compounding the high ambient humidity of the past week (averaging 81%).
- South-facing sections will dry faster than the NW-facing walls, but the below-road runoff issue affects all aspects — check the crag top for dampness before committing.
Warnings
2
- The rock surface may appear dry while remaining saturated internally — the 'scrittle' (loose grit on holds) is a clear sign the rock has not dried sufficiently and holds may break.
- Repeated recent wetting events over the past two weeks mean cumulative moisture loading is high; do not trust surface appearance alone.
Reasoning
With 2.7mm of rain today, 2.0mm on Aug 6, and 5.5mm on Aug 4 — all following a 14.7mm event on July 26 — the rock has had no meaningful drying window and will be saturated internally, especially given the below-road-level runoff channelling.
Despite moderate SW winds (19–24 km/h), the sheltered position negates much of the wind benefit, and persistent humidity around 75–81% over the past week has severely limited evaporative drying between rain events.
The particularly friable and porous nature of this crag means hold breakage risk is elevated; even at low internal saturation levels the iron-oxide cemented holds can fail, and the 'scrittle' phenomenon indicates grain loosening is already occurring.
Mid-summer temperatures (14–21°C) are adequate for drying in principle, but the frequent rain interruptions and high humidity have prevented the sustained dry period this crag specifically requires.
Contributing Factors
6
2.7mm fell today with no dry days accumulated, following 2.0mm on Aug 6 and 5.5mm on Aug 4, keeping the rock repeatedly re-wetted.
The crag's sheltered, sunken position traps humid air and channels road-level runoff onto the face, dramatically slowing drying compared to exposed crags.
Average humidity of 81% over the last seven days severely limits net evaporation from the rock surface.
This crag's sandstone is noted as more porous and friable than typical Northumberland Fell Sandstone, making it especially vulnerable to moisture-related hold failure and 'scrittle' formation.
Temperatures in the 14–21°C range are sufficient to support drying if rain ceases and humidity drops.
Winds of 19–24 km/h from SW would normally aid drying but are largely blocked by the sheltered position of the crag.
Recommendations
3
- Do not climb today or tomorrow — the rock needs at minimum 48 hours of completely dry weather with lower humidity before conditions can be reassessed.
- Before any visit later this week, check the crag top and base of the cliff for dampness; if the ground at the base is not bone-dry and sandy, the rock is still wet internally.
- Avoid top-roping entirely until conditions have been dry for several days — the soft Fell Sandstone at Corby's is especially susceptible to rope-groove damage when damp.
Do Not Climb
35%
6 days ago
Corby's Crag has received repeated light-to-moderate rain over the past week (8.6mm across several events, including 5.5mm on Aug 4, 2.0mm on Aug 6, and 0.3mm today), with only one fully dry day since. Given the crag's sheltered, below-road-level position, high porosity, and runoff channelling from above, the rock is very likely still holding internal moisture and we recommend not climbing today.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- The below-road-level position channels runoff from above onto the face, meaning the crag receives more water than open-air rainfall totals suggest — it can be wet even when nearby crags are dry.
- The rock here is noted as more friable and porous than typical Northumberland sandstone, and develops 'scrittle' (loose surface grit) after rain that persists even when the surface appears dry.
- The sheltered aspect significantly reduces airflow at the rock face despite moderate regional winds, meaning effective drying rates are much slower than the wind data alone would suggest.
- The south-facing sections will dry substantially faster than the NW-facing sections — assess each aspect independently and consider starting on south-facing routes if conditions permit.
Warnings
2
- The rock surface may appear dry while remaining internally saturated — do not trust visual appearance alone at this crag.
- Scrittle (loose surface grit) after recent rain makes holds unreliable and indicates the rock has not adequately dried — retreat if you encounter this.
Reasoning
With 5.5mm on Aug 4, 2.0mm on Aug 6, and trace amounts today (0.3mm), plus runoff channelling from above, the rock almost certainly retains significant internal moisture despite brief dry intervals.
Although regional winds have been moderate (20–35 km/h SW/W), the sheltered below-road-level position means very little of this wind reaches the rock face, and humidity has averaged 80% over the past week — effective drying has been poor.
The friable, high-porosity Fell Sandstone at Corby's is at elevated risk of hold breakage and surface damage given the repeated wetting cycles and likely internal saturation above the critical threshold for strength loss.
Summer temperatures (~14–20°C) are adequate for drying in principle, but the persistent high humidity and frequent rain events in this period have negated the seasonal advantage.
Contributing Factors
6
Multiple rain events over the past 5 days (5.5mm on Aug 4, 0.5mm Aug 5, 2.0mm Aug 6, 0.3mm today) have kept the rock in a near-continuous wetting cycle with no sustained dry spell.
The crag sits below road level in a sheltered hollow, dramatically reducing effective wind exposure at the rock face and slowing evaporation despite moderate regional winds.
The below-road-level position funnels surface runoff onto the crag, delivering more water than rainfall totals alone indicate and prolonging internal saturation.
Average humidity of 80% over the past week significantly limits evaporative drying potential, especially in the sheltered microclimate.
Temperatures in the 14–20°C range provide reasonable thermal energy for drying, though this is largely offset by humidity and shelter.
Regional winds of 19–36 km/h are helpful in theory but the sheltered position means little of this reaches the rock face.
Recommendations
3
- Do not climb today — wait for at least 48 hours of genuinely dry weather with no further rain before reassessing.
- If visiting later in the week, check the crag top and base for dampness before committing; if the ground at the base is moist or holds feel gritty ('scrittle'), the rock is still too wet.
- Prioritise south-facing sections first when conditions do improve, and avoid top-roping on this particularly soft sandstone.
Do Not Climb
70%
7 days ago
Corby's Crag received 2.0mm of rain yesterday (Aug 6) and 5.5mm on Aug 4, with only one full dry day since. Given the crag's sheltered, below-road-level position and the friable, highly porous nature of this particular Fell Sandstone, the rock is very likely still damp internally despite today's improving conditions. We recommend waiting.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Corby's below-road-level position channels runoff from the road and surrounding ground onto the rock face, meaning it can remain wet even when nearby crags have dried out.
- This outcrop is noted as more friable and porous than typical Northumberland sandstone, developing 'scrittle' (loose grit) on holds after rain that persists even when the surface looks dry — a sustained dry spell is needed to clear this.
- The sheltered aspect greatly reduces airflow across the rock face, significantly slowing evaporation compared to exposed crags despite today's moderate SW wind.
- The south-facing sections will dry notably faster than the NW-facing sections; if conditions improve, south-facing routes should be considered first.
Warnings
2
- Do not climb today — the rock is almost certainly still damp internally despite surface appearances, and Corby's friable sandstone is at high risk of hold breakage and permanent route damage.
- Avoid top-roping at this crag even in dry conditions as the soft Fell Sandstone is particularly susceptible to rope abrasion damage.
Reasoning
With 2.0mm on Aug 6, 0.5mm on Aug 5, and 5.5mm on Aug 4 — totalling 8.0mm in the last three days — the rock almost certainly retains significant internal moisture, especially given only one dry day and the crag's tendency to receive runoff from above.
Today's SW wind at 24.5 km/h is helpful but the sheltered position means the crag face itself sees much less airflow; combined with 74% humidity and only moderate temperatures (~17°C), one day is far too little drying time for this particularly porous and friable sandstone after recent cumulative rainfall.
The rock at Corby's is noted as more friable than typical Fell Sandstone, and with internal moisture likely still present, hold breakage risk is elevated — iron oxide cemented holds are especially vulnerable when the surrounding matrix is weakened.
Summer conditions are generally favourable for drying, but the recent unsettled spell with high humidity (averaging 80% over the last week) and below-average temperatures has significantly limited drying potential.
Contributing Factors
6
8.0mm fell across Aug 4–6 with the most recent rain (2.0mm) only yesterday, giving just one full dry day — far short of the 48–72+ hours needed for this porous rock.
The crag sits below road level in a sheltered hollow that channels runoff onto the face and severely limits air circulation, greatly prolonging drying time.
Average humidity over the past week has been 80%, sharply reducing evaporation rates and keeping the rock's internal moisture levels elevated.
Today's 24.5 km/h SW wind will help surface drying somewhat, though the sheltered position means the crag face receives only a fraction of this.
Temperatures around 17°C provide reasonable evaporative potential, though the last week has averaged only 13.7°C which is below typical for August.
Corby's sandstone is noted as more friable and porous than typical Fell Sandstone, meaning it absorbs water faster and is more vulnerable to strength loss when damp.
Recommendations
3
- Wait at least 2–3 more completely dry days before visiting; the rock needs sustained dry, breezy weather to clear internal moisture and the characteristic post-rain 'scrittle'.
- If you visit after adequate drying, check the crag top and base for dampness before committing — if the ground at the base is moist, the rock is still wet internally.
- Prioritise south-facing routes first as these will dry significantly faster than the NW-facing sections.
Do Not Climb
45%
9 days ago
Corby's Crag received 5.5mm on August 4th and a further 0.5mm on August 5th, with only one full dry day elapsed since; given the crag's sheltered, below-road-level position and high average humidity (~79%), the rock is very likely still damp internally despite potentially appearing surface-dry. We recommend waiting for further drying before climbing.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- The below-road-level position channels runoff from the road and surrounding ground onto the rock face, meaning the crag can be wet even when nearby crags appear dry.
- The rock at Corby's is noted as more friable and porous than most Northumberland Fell Sandstone, and develops 'scrittle' (loose surface grit) after rain that persists even when the surface looks dry.
- The sheltered aspect greatly reduces wind-assisted drying — today's moderate westerly winds (27 km/h ambient) will be significantly attenuated at the crag base.
- The south-facing sections will dry considerably faster than the NW-facing sections; if conditions improve, check the south-facing walls first but treat the NW faces as still damp.
Warnings
2
- The rock may appear surface-dry while remaining saturated internally — do not be deceived by dry-looking holds; the 'scrittle' phenomenon at this crag is a reliable indicator that the rock is still compromised.
- Repeated wet spells since late July mean deep moisture reserves may persist even after the surface dries — test holds carefully and retreat if grit comes away on your fingers.
Reasoning
With 5.5mm on Aug 4th and 0.5mm on Aug 5th, only ~24 hours of dry weather have elapsed — far short of the 48–72+ hours needed for this sheltered, porous crag to dry internally.
Despite moderate westerly winds aloft, the sheltered below-road-level position will greatly reduce effective airflow at the rock face, and average humidity of 71–80% over the last two days further slows evaporation.
The noted friability and high porosity of this particular outcrop mean hold breakage risk remains elevated; the 'scrittle' phenomenon indicates surface grain loosening is active after recent rain.
Mid-summer temperatures (~16°C) are moderate but not high enough to drive rapid drying, especially given persistent cloud cover and humidity levels around 70–80%.
Contributing Factors
6
5.5mm on Aug 4th plus 0.5mm on Aug 5th totalling 6mm in two days, with only one dry day since — insufficient drying time for porous Fell Sandstone.
The crag's sheltered, sunken setting significantly reduces wind-assisted drying and channels additional runoff onto the rock face.
Average humidity of ~79% over the past week severely limits evaporative drying capacity, especially in still air at the crag.
27 km/h westerly winds today provide some drying potential, though the sheltered position will attenuate this significantly at the rock face.
Temperatures of 14–16°C are adequate but not exceptional for driving evaporation, particularly under persistent 100% cloud cover.
14.7mm fell on July 26th, and the subsequent drying period was interrupted by further rain on Jul 28-29 and Aug 3-5, so deep moisture reserves may not have fully cleared.
Recommendations
3
- Wait at least another 24–48 hours of dry, breezy weather before visiting — ideally until August 8th or later if humidity remains high.
- If you do visit, check the crag top and base for dampness before committing; if the ground at the base is moist or the top is seeping, do not climb.
- Avoid top-roping entirely on this soft Fell Sandstone crag, especially in current marginal conditions when the rock is at its weakest.
Do Not Climb
92%
11 days ago
Corby's Crag has received rain today (3.2mm including showers through the early hours and midday) on top of recent heavy rain on July 26th (14.7mm) and intermittent light showers since, with the sheltered below-road-level position meaning the rock will be thoroughly wet. With more rain forecast tomorrow (4.2mm) and further showers through the week, there is no adequate drying window in sight.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Corby's below-road-level position channels runoff from the road and surrounding ground onto the rock face, meaning the crag can remain wet even when nearby crags have dried.
- The rock here is notably more friable and porous than typical Northumberland Fell Sandstone, developing 'scrittle' (loose surface grit) after rain that persists long after the surface appears dry — a long sustained dry spell is needed to clear this.
- The sheltered setting with minimal air circulation significantly retards drying; the predominantly NE winds of recent days would not penetrate well to the NW-facing sections.
- South-facing sections will dry faster than NW-facing ones, but the below-road runoff issue affects the entire crag regardless of aspect.
Warnings
3
- Climbing on wet Fell Sandstone causes permanent, irreversible damage to holds and routes — this crag's notably friable rock makes it even more vulnerable than other Northumberland venues.
- The surface may appear dry while the interior remains saturated — do not be deceived by a dry-looking surface, especially at this crag where 'scrittle' indicates ongoing internal moisture issues.
- Runoff from the road above can keep the rock face wet even when no direct rain has fallen — always check the crag top for dampness before committing.
Reasoning
The rock is almost certainly saturated — today's 3.2mm of rain fell on stone that had not fully dried from showers on August 3rd (0.3mm), July 28th (1.2mm), and the heavy 14.7mm event on July 26th, with the sheltered position and high humidity (77% average over the past week) preventing effective drying between events.
Despite some moderate winds (19–22 km/h westerly) on July 30–August 2, the sheltered position would have greatly reduced their effect at the crag face, and humidity remained high (66–74%); the intermittent showers have continually reset any drying progress.
With the rock likely at or near saturation, compressive strength will be reduced by 30%+ and the notably friable nature of this particular outcrop means hold breakage and surface damage are a serious risk — climbing now would cause permanent damage.
Summer temperatures (14–21°C) would normally aid drying, but the persistent cloud cover (100% today), high humidity, and repeated rain events are negating this seasonal advantage.
Contributing Factors
7
3.2mm of rain has fallen today including showers through the early hours and around midday, with the rock currently wet.
14.7mm fell on July 26th and the crag has not had a sustained dry period since, with light showers on July 27, 28, 29, August 3, and today continually re-wetting the surface.
The below-road-level sheltered setting means wind has minimal effect on evaporation, and runoff from above adds additional moisture the crag itself didn't receive as direct rainfall.
Average humidity over the past 7 days is 77% with today reaching 89–98% through much of the day, severely limiting evaporative drying.
4.2mm is forecast tomorrow, 1.5mm on the 6th, 0.7mm on the 8th, and 6.2mm on the 9th — no sustained drying window exists in the next 5 days.
This crag's rock is noted as more friable and porous than typical Fell Sandstone, making it especially vulnerable to moisture damage and slow to reach climbable condition.
Temperatures of 15–21°C are reasonable for drying but are being negated by persistent cloud cover and humidity.
Recommendations
3
- Do not climb at Corby's Crag today or in the coming days — the rock is wet and the forecast offers no adequate drying window this week.
- Wait for a sustained period of at least 3–4 dry days with lower humidity and some wind before visiting; given this crag's sheltered position and friable rock, extra caution beyond normal Fell Sandstone guidelines is warranted.
- If visiting the Northumberland area this week, consider non-sandstone alternatives such as Bowden Doors' whinstone or The Wanneys only after proper drying — but check conditions carefully everywhere given the unsettled weather.
Do Not Climb
72%
12 days ago
Despite a good dry spell from July 30–August 2, heavy rain on July 26 (14.7mm) followed by further light showers on July 27–29, today's morning drizzle (0.7mm), and 9.6mm forecast tomorrow mean the rock is unlikely to be properly dry — and conditions are about to get significantly worse. The sheltered, below-road-level position at Corby's means drying has been slow and runoff from above may still be feeding moisture onto the face.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Corby's sits below road level, channelling runoff from the road and hillside above directly onto the rock face — this crag can be wet even when nearby crags are dry.
- The notably friable and porous rock here develops 'scrittle' (loose grit on holds) after rain, which persists even after the surface looks dry and requires an extended dry spell with wind to clear.
- The sheltered position means wind assistance for drying is significantly reduced compared to exposed Northumberland crags, so published drying guidelines should be treated as minimums.
- South-facing sections will dry faster than the NW-facing walls — if conditions are borderline, the south aspect is the place to check first, but the NW face could remain damp for days longer.
Warnings
2
- 9.6mm of rain is forecast tomorrow (August 4) which will deeply re-saturate this already marginal rock — do not plan to climb this week.
- Corby's friable sandstone develops scrittle after rain that makes holds unreliable even when the surface looks dry — trust touch not sight.
Reasoning
The 14.7mm event on July 26 would have deeply saturated this porous, friable sandstone, and subsequent light rain on July 27–29 plus today's drizzle has prevented a clean drying window from establishing.
The best drying window was July 30–August 2 (four dry days with moderate W/SW wind and temps 16–18°C), but the sheltered position limits wind penetration, humidity stayed 66–74%, and today's renewed moisture resets the clock.
Given Corby's is noted as more friable and porous than typical Fell Sandstone, the risk of hold breakage and scrittle formation is elevated — the rock may feel gritty even where surfaces appear dry.
Mid-summer temperatures are adequate for drying but the current unsettled pattern with high humidity (87% today, 90% forecast tomorrow) is suppressing evaporation at a critical time.
Contributing Factors
7
14.7mm on July 26 deeply saturated this highly porous sandstone and the below-road-level position would have concentrated additional runoff.
Light showers on July 27 (0.2mm), July 28 (1.2mm), July 29 (0.1mm), and today (0.7mm) have prevented a clean drying window from fully establishing.
The below-road-level sheltered setting significantly reduces wind-assisted drying despite moderate regional winds of 19–22 km/h over the past few days.
9.6mm forecast for August 4 with 90% humidity will re-saturate the rock and reset any drying progress.
Temperatures of 16–18°C over the past few days are reasonable for evaporative drying, though the sheltered position and high humidity reduce the benefit.
Today's average humidity of ~87% with 100% cloud cover severely limits evaporation, especially in a sheltered hollow.
Further rain is forecast on August 5 (0.7mm), August 6 (1.7mm), August 7 (0.6mm), and August 8 (5.4mm), meaning no meaningful drying window is expected this week.
Recommendations
3
- Do not climb at Corby's today or this week — the forecast shows no adequate drying window until at least August 9 and conditions will worsen significantly after tomorrow's heavy rain.
- If visiting the area, consider non-porous alternatives such as the whinstone at Great Wanney or Crag Lough, which are structurally unaffected by moisture (though still slippery when wet).
- Before any future visit after a dry spell, check the crag top and base for dampness and run your hand across holds to test for scrittle — if grit comes away, the rock is not ready.
Climbing Outlook