Condition Analysis
AI-powered assessment using site data and 14-day weather history
Crag Lough has received frequent light precipitation over the past week (13.9mm in 7 days, including 1.9mm yesterday and 1.1mm forecast today) with no meaningful dry spell, and the north-facing aspect at 260m means surface moisture will linger despite the exposed position. The dolerite won't be damaged but is likely to be greasy and slippery, making climbing inadvisable today.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Crag Lough's north-facing aspect receives virtually no direct sun in early April, so surface water and seepage from the cliff top rely almost entirely on wind to dry — with today's moderate southerly wind the face itself is somewhat sheltered.
- The crag sits atop the Whin Sill escarpment where drainage from the moorland above feeds seepage lines between buttresses, which will be active after this prolonged wet spell.
- Peregrine falcons nest at Crag Lough in spring — climbers must check the BMC Regional Access Database (RAD) for current seasonal restrictions before approaching any buttress.
- The lough at the base creates a humid microclimate on the north face, further slowing drying compared to what the regional weather data alone might suggest.
Warnings
3
- Dolerite becomes extremely slippery when wet — even a thin moisture film invisible to the eye can cause friction loss and a serious fall.
- Peregrine nesting restrictions may be in effect at Crag Lough — check the BMC RAD before visiting; violating these can result in permanent access loss.
- Active freeze-thaw has been loosening blocks at the crag base; take extra care beneath the cliff and when pulling on detached features.
Reasoning
With 1.9mm yesterday (scattered showers throughout the day), 1.1mm today, and no consecutive dry days, the rock surface is almost certainly damp, particularly in cracks, on ledges, and below seepage lines.
Although the site is exposed, today's 24.8 km/h southerly wind hits the north face obliquely at best, and the north aspect receives minimal solar heating in early April, meaning drying will be slow and incomplete.
Whin Sill dolerite does not suffer structural weakening when wet, but active freeze-thaw at the crag base (min temps near or below 0°C several nights recently) means loose blocks remain a hazard at the foot of the crag.
Early April at 260m in Northumberland is still marginal for reliable drying; overnight temperatures have been near freezing, humidity averages 78% over the past week, and peregrine nesting restrictions may close sections of the crag.
Contributing Factors
7
No consecutive dry days; 13.9mm in the last 7 days with rain on most days including yesterday (1.9mm) and today (1.1mm), keeping the rock surface persistently damp.
The north face receives negligible direct sun in early April, dramatically reducing solar-driven evaporation and leaving moisture to persist on the rock.
Whin Sill dolerite absorbs virtually no moisture, meaning surface water can be cleared quickly by wind once precipitation stops — no risk of structural damage.
The high, exposed position on the Whin Sill escarpment provides good wind exposure that aids surface drying, partially compensating for the lack of sun.
Average humidity of 78% over the past week with 77% today limits evaporative drying potential, and the lough below adds local moisture.
1.1mm forecast for today means the rock is unlikely to achieve a dry state at any point during the day.
Several recent nights below or near 0°C (including -1.3°C on April 6 and -1.8°C on April 2) mean freeze-thaw cycling is actively loosening blocks at the crag base.
Recommendations
3
- Wait for a spell of at least one full dry day with moderate wind before attempting routes — the forecast suggests April 17 may offer the first realistic window.
- Check the BMC RAD for current peregrine nesting restrictions at Crag Lough before planning any visit; sections may be closed until June.
- If you do visit, test friction carefully on the lower holds first — dolerite can appear dry to the eye but remain treacherously slippery with a thin moisture film.
Previous Analyses
Do Not Climb
45%
2 days ago
Crag Lough has received light but persistent rainfall over the past week (11.4mm in 7 days), with 0.5mm today and 4.1mm of rain on April 11 — there have been zero consecutive dry days. While dolerite is non-porous and dries quickly in principle, the north-facing aspect, high humidity, and lack of any sustained dry spell mean surface moisture and seepage are very likely present, making the rock dangerously slippery.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Crag Lough's north-facing aspect receives virtually no direct sun in early spring, meaning surface moisture from seepage and condensation lingers far longer than on south-facing whinstone crags.
- The crag sits on the exposed Whin Sill ridge where strong westerly/south-westerly winds aid surface drying, but today's wind is from the SW which will be partially deflected by the north-facing orientation, reducing its drying effect on the climbing faces.
- Active freeze-thaw is a concern at this time of year — overnight lows have dropped below zero several times recently (e.g. -1.3°C on April 6, -1.8°C on April 2), loosening blocks at the crag base and on ledges.
- This is peregrine falcon nesting season at Crag Lough — climbers must check the BMC Regional Access Database (RAD) for current bird restrictions before visiting, as sections of the crag may be closed.
Warnings
3
- Dolerite becomes extremely slippery when even slightly damp — a fall due to friction loss on apparently dry-looking rock is a serious risk.
- Active freeze-thaw means loose blocks at the crag base and on ledges pose a genuine hazard; wear a helmet and be cautious below the crag.
- Peregrine nesting restrictions are likely in effect — climbing on restricted sections could result in prosecution and loss of access for all climbers.
Reasoning
With 0.5mm of precipitation today, 4.1mm yesterday, and no consecutive dry days, the rock surface is almost certainly damp, particularly on the north-facing walls where drainage seepage and condensation accumulate.
Despite strong winds (37 km/h SW today), the north-facing aspect shields the climbing surfaces from both direct sun and the prevailing wind direction, severely limiting drying potential — dolerite needs only surface drying but the conditions haven't allowed even that.
Dolerite does not weaken when wet, but recent freeze-thaw cycles with sub-zero overnight temperatures (multiple nights below 0°C in the past two weeks) increase the risk of loose blocks at the crag base and on ledges.
Early April at 260m in Northumberland is still firmly in the transitional season with short days, low sun angles, high humidity, and frequent precipitation — conditions are marginal at best for north-facing crags.
Contributing Factors
7
Zero consecutive dry days with light but repeated precipitation (11.4mm over 7 days including 4.1mm yesterday and 0.5mm today) means the rock surface has had no chance to fully dry.
The north-facing orientation receives no direct sun in early spring, drastically reducing evaporative drying and allowing moisture to persist on the climbing surfaces.
Whin Sill dolerite absorbs virtually no water so only surface moisture needs to clear, meaning a few dry windy hours could bring conditions into climbing territory.
The exposed ridge position and 37 km/h winds today aid surface evaporation, partially offsetting the lack of sun on the north face.
Average humidity of 77% over the past week with 78% today limits evaporative drying and may cause condensation on cold north-facing rock.
Multiple sub-zero overnight lows in recent weeks have driven active freeze-thaw cycles, increasing the hazard from loose blocks at the crag base.
Crag Lough is a known peregrine nesting site and April falls within the February–June restriction period, so access to parts of the crag may be prohibited.
Recommendations
3
- Do not climb today — wait for a sustained dry period of at least 12–24 hours with wind to allow surface moisture to clear from the north-facing rock.
- Check the BMC Regional Access Database for current peregrine nesting restrictions at Crag Lough before planning any visit.
- If visiting later in the week, test friction carefully on lower holds before committing to routes — dolerite can appear dry while retaining a thin film of moisture that destroys friction.
Do Not Climb
70%
3 days ago
Crag Lough is currently wet from today's 3.4mm rainfall with zero consecutive dry days, and the north-facing aspect at 260m will retain surface moisture. While dolerite doesn't suffer structural damage, the dense black rock will be extremely slippery and the strong southerly wind won't effectively dry this north-facing crag.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Crag Lough is a peregrine nesting site — check the BMC Regional Access Database for active seasonal restrictions before visiting, as spring closures (typically February–June) may be in effect.
- The north-facing aspect means virtually no direct sun reaches the rock face in early April, so surface moisture from today's rain and recent wet spells will linger far longer than on south-facing crags.
- The exposed Whin Sill ridge catches strong winds which help surface drying, but today's southerly wind is less effective on north-facing rock than the prevailing westerlies would be.
- Loose blocks at crag bases are a persistent hazard — the recent cycle of overnight frosts (min -1.3°C on April 6, -1.8°C on April 2) and daytime thawing actively promotes freeze-thaw spalling on dolerite columns.
Warnings
3
- Peregrine nesting restrictions may be in effect — check BMC RAD before visiting; climbing during a closure damages access agreements at this Heritage Site.
- Dolerite is extremely slippery when wet; a fall due to friction loss on damp holds is a serious risk today.
- Loose blocks at crag bases are an active hazard following recent freeze-thaw cycling.
Reasoning
With 3.4mm of rain today and 0.4mm yesterday, the rock surface is currently wet; the recent pattern shows 11.9mm over the past 7 days with no meaningful dry spell to clear accumulated seepage.
Although dolerite is non-porous and can dry within hours, the north-facing aspect receives no direct sun in early April, and today's strong southerly wind (40 km/h) will not effectively scour this sheltered north face, meaning surface drying will be slow.
Dolerite does not weaken structurally when wet, but recent freeze-thaw cycling (overnight lows down to -1.8°C in the past week with daytime highs above 10°C) increases the risk of loose block detachment at crag bases.
Early April is a transitional period with unreliable conditions; overnight frosts are still possible, peregrine nesting restrictions may apply, and the low sun angle provides minimal drying benefit to this north-facing crag.
Contributing Factors
7
3.4mm today and 0.4mm yesterday mean the rock surface is currently wet with no drying window.
The north-facing orientation receives virtually no direct sunlight in early April, greatly slowing evaporation of surface moisture.
The 40 km/h southerly wind provides some drying potential but is less effective on a north-facing crag sheltered from southerlies by the Whin Sill ridge itself.
Whin Sill dolerite absorbs almost no water, so once surface moisture clears the rock will be climbable — but it is extremely slippery while damp.
74mm over the past 28 days with frequent rain events means persistent ground saturation and likely seepage from the crag top.
Overnight lows near or below freezing in recent days combined with daytime thawing increases loose block hazard at crag bases.
Crag Lough is a known peregrine nesting site and seasonal access restrictions are likely in effect during April — always check BMC RAD.
Recommendations
3
- Do not climb today — the rock will be wet and dangerously slippery; wait for a dry window of at least several hours with some breeze.
- Check the BMC Regional Access Database for active peregrine nesting restrictions before planning any visit to Crag Lough this spring.
- If visiting later this week after a dry spell, test friction carefully on lower holds before committing and beware of loose blocks at crag bases following recent freeze-thaw cycles.
Do Not Climb
45%
4 days ago
Yesterday saw 6.4mm of rain and today has had 0.3mm of precipitation, with the north-facing aspect receiving minimal sun to aid drying. While dolerite doesn't absorb water, surface moisture and seepage are likely still present, making the rock dangerously slippery.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Crag Lough's north-facing aspect means it receives virtually no direct sun in early April, so surface moisture from yesterday's 6.4mm rain and today's drizzle will linger on ledges, cracks, and seepage lines.
- The Whin Sill dolerite becomes exceptionally slippery when damp — the dense black rock offers very poor friction even with a thin moisture film, and conditions can be deceptive as the rock may look dry while still being greasy.
- Peregrine falcons nest at Crag Lough in spring — climbers must check the BMC Regional Access Database (RAD) for current seasonal restrictions before visiting, as sections of the crag may be closed.
- Loose blocks at the base of the buttresses are a particular hazard in early spring following winter freeze-thaw cycles; the recent overnight frosts (down to -1.8°C on April 2nd and -1.3°C on April 6th) may have loosened additional material.
Warnings
3
- Dolerite is extremely slippery when damp — even a thin moisture film can cause sudden, unexpected slips on what appears to be dry rock.
- Peregrine nesting restrictions are likely active at Crag Lough in April — climbing on restricted buttresses risks prosecution and loss of access for all climbers.
- Loose blocks at the crag base pose a serious hazard following recent freeze-thaw cycles; wear helmets and exercise caution on approach.
Reasoning
With 6.4mm of rain yesterday and 0.3mm today, the non-porous dolerite surface is likely still carrying residual moisture in cracks, on ledges, and along seepage lines, particularly on this north-facing aspect.
The exposed ridge position and moderate SW winds (~30 km/h) will help strip surface water, but the north-facing aspect and lack of direct sun severely limit evaporative drying — dolerite typically needs only hours to dry in sun and wind, but several hours more on a shaded north face.
Dolerite does not weaken when wet, but recent overnight frosts interspersed with wet periods increase the risk of loosened blocks at the crag base from freeze-thaw action.
Early April in Northumberland brings short, cool days with limited solar angle on north faces; peregrine nesting restrictions are active and must be checked before any visit.
Contributing Factors
7
6.4mm fell on April 9th and 0.3mm today, meaning the rock surface has had less than 24 hours to dry from a significant shower.
The north-facing orientation receives negligible direct sunlight in early April, dramatically slowing surface evaporation compared to south-facing crags.
SW winds around 30 km/h across the exposed Whin Sill ridge will help strip surface moisture, partially compensating for the lack of sun.
Whin Sill dolerite does not absorb water, so drying is purely a surface phenomenon and occurs much faster than on sandstone or gritstone.
Humidity has dropped to 72% today from 91% yesterday, aiding surface evaporation.
Recent overnight frosts down to -1.8°C amid wet periods increase the likelihood of loosened blocks at the crag base.
April is peak peregrine nesting season at Crag Lough; access restrictions may be in place on some buttresses.
Recommendations
3
- Wait at least one full dry day with wind before visiting — the forecast rain tomorrow (7.5mm) will reset drying progress, so April 14th or 15th look more promising.
- Check the BMC Regional Access Database for current peregrine nesting restrictions at Crag Lough before planning any visit.
- If visiting in the coming days, carry a towel and test friction carefully on lower holds before committing to any route — dolerite can feel deceptively dry while still being dangerously greasy.
Do Not Climb
55%
5 days ago
Today's 3mm of rain on a north-facing, exposed crag at 260m means the rock is likely wet right now; although dolerite dries quickly, the combination of high humidity overnight (96%), today's precipitation, and the north aspect makes surface conditions unreliable. Climbers should wait for a dry window — tomorrow looks far more promising.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Crag Lough is a peregrine nesting site and it is now April — check BMC RAD for any active seasonal restrictions before visiting.
- The north-facing aspect receives virtually no direct sun in early spring, meaning any surface moisture from today's rain will rely entirely on wind evaporation to dry.
- The exposed ridge position along Hadrian's Wall means strong westerly winds can strip surface moisture quickly, but can also drive rain and mist directly onto the crag face.
- Active freeze-thaw at crag bases remains a hazard — overnight lows are still dropping near or below 0°C, and loose blocks at the base should be treated with caution.
Warnings
3
- Dolerite becomes extremely slippery when wet — do not attempt friction-dependent routes if any surface moisture is present.
- Peregrine nesting restrictions may be in effect — check BMC Regional Access Database before visiting.
- Active freeze-thaw and loose blocks at crag bases pose a falling debris hazard; wear a helmet on approach.
Reasoning
Today has seen 3mm of rain with 87% humidity, and overnight humidity reached 96%, meaning the rock surface is almost certainly damp or wet right now.
Although the crag is exposed to 32 km/h westerly winds which aid drying, the north aspect receives negligible direct sun in early April, so drying depends entirely on wind — and with rain falling today, the surface is unlikely to be reliably dry until well into a dry tomorrow.
Whin Sill dolerite does not suffer structural weakening when wet, but active freeze-thaw at crag bases with overnight lows near 0°C means loose blocks remain a hazard.
Early April at 260m on a north-facing crag is still marginal season — short days, low sun angle, and overnight temperatures near freezing all slow drying and increase condensation risk.
Contributing Factors
7
3mm of precipitation today with 87% humidity means the rock surface is currently wet.
Humidity rose to 96% overnight and into this morning, likely depositing condensation on the cold north-facing rock.
No direct sun reaches the crag in early spring, eliminating solar drying and leaving only wind evaporation.
Strong 32 km/h westerly winds on the open ridge will help strip surface moisture once rain stops.
Whin Sill dolerite absorbs virtually no water, so surface moisture can evaporate within hours once conditions improve.
April 6–8 were completely dry with warm temperatures up to 16°C, meaning the crag was well-dried before today's rain.
Overnight lows near 0°C mean freeze-thaw cycles are still active, increasing loose block hazard at crag bases.
Recommendations
3
- Wait until tomorrow (April 10) when a dry day with 72% humidity and moderate SW winds should allow the dolerite to dry within a few hours of daylight.
- If visiting today, be prepared to walk away — dolerite is extremely slippery when wet and friction-dependent moves become dangerous.
- Check BMC RAD for active peregrine nesting restrictions at Crag Lough before making the journey, as April is peak nesting season.
Marginal — Assess Conditions
62%
6 days ago
Two full dry days (Apr 6–7) with good temperatures and moderate wind should have cleared surface moisture from the non-porous dolerite, but today's 0.3mm precipitation and 82% humidity introduce uncertainty. A visual check on arrival is strongly recommended before committing to climb.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Crag Lough is north-facing at 260m on an exposed ridge, so even after dry spells the rock receives almost no direct sun in early spring and can retain a greasy film from condensation or mist.
- The Whin Sill dolerite here is notoriously slick when even slightly damp — the dense black rock gives very little friction warning before feet skate, making visual and tactile assessment essential.
- Peregrine falcons nest at Crag Lough in spring; climbers must check BMC RAD for current restrictions before visiting, as sections of the crag may be closed from February through June.
- Active freeze-thaw at the crag base remains a concern in early April — overnight lows have dropped below zero several times recently (−1.3°C on Apr 6, −1.8°C on Apr 2), loosening blocks at the base and on ledges.
Warnings
2
- Peregrine nesting restrictions may be in force at Crag Lough — check BMC RAD before visiting; climbing near active nest sites is illegal under the Wildlife and Countryside Act.
- Loose blocks from active freeze-thaw pose a serious hazard at the crag base and on ledges; helmets are essential.
Reasoning
The dolerite surface should be largely dry after two fully dry days (Apr 6–7) with temperatures reaching 11.6°C and 15.9°C respectively, but today's trace precipitation (0.3mm) and 82% humidity may leave a damp film on the north-facing rock.
Moderate winds (15–22 km/h) from the south and east over the last two days would have aided surface drying on this exposed ridge, though the north-facing aspect means the rock received no direct sun to warm and evaporate residual moisture.
Dolerite does not suffer structural weakening when wet, but recent overnight sub-zero temperatures (−1.3°C on Apr 6) mean freeze-thaw loosening of blocks at the crag base and on ledges remains a live hazard.
Early April in Northumberland brings unpredictable conditions with lingering winter characteristics; the 98mm of rain over the past 28 days reflects a very wet period, and overnight frost risk persists at 260m altitude.
Contributing Factors
6
April 6 and 7 were completely dry with good temperatures (up to 15.9°C), giving the non-porous dolerite ample time to shed surface water.
Today (Apr 8) shows 0.3mm precipitation which, while minimal, could leave a thin damp film on the slick north-facing dolerite.
The north-facing orientation at 260m means the rock receives virtually no direct sun in early April, relying entirely on wind and ambient temperature for drying.
The highly exposed position on the Whin Sill ridge means moderate winds (15–22 km/h) efficiently strip surface moisture from the non-porous rock.
Average humidity of 80% over the past week and 82% today limits evaporative drying and may cause condensation on cold north-facing rock surfaces.
Recent overnight temperatures dropping below zero (−1.3°C on Apr 6) drive active freeze-thaw cycles that loosen blocks at the crag base and on ledges.
Recommendations
3
- Visually and tactilely check the rock surface on arrival — run your palm across holds to test for the greasy film that dolerite develops when damp; if it feels slick, do not climb.
- Check BMC Regional Access Database for current peregrine nesting restrictions at Crag Lough before your visit, as closures are likely active in April.
- Be vigilant for loose blocks at the crag base and on ledges, as recent freeze-thaw cycles have been active; wear a helmet on the approach and while belaying.
Marginal — Assess Conditions
65%
8 days ago
Light showers yesterday (1.7mm) ended by early evening, and the exposed ridge with strong winds will have dried the non-porous dolerite surface reasonably quickly. However, overnight humidity rose to 93% with temperatures near freezing, so residual dampness, condensation, or even a light frost glaze on the north-facing rock is possible — a visual check on arrival is essential.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Crag Lough is a peregrine nesting site — it is early April and nesting restrictions are very likely in effect; check BMC RAD for current closures before visiting.
- The north-facing aspect receives virtually no direct sun in early spring, meaning overnight condensation and frost can linger well into the morning on the rock surface.
- The crag sits on the Whin Sill escarpment and is a UNESCO World Heritage Site (Hadrian's Wall); tread carefully on approach paths and respect heritage restrictions.
- Loose blocks at the base are common here and recent freeze-thaw cycles (overnight lows to -3°C in the past fortnight) may have destabilised additional material.
Warnings
2
- Peregrine nesting restrictions are very likely active at Crag Lough in April — verify with BMC RAD before visiting or you risk causing disturbance and jeopardising access.
- Overnight temperatures dropped below freezing; thin ice or frost may coat the north-facing rock surface and will be nearly invisible on dark dolerite.
Reasoning
The last meaningful rain was 1.7mm yesterday spread across the day as light showers, with the final precipitation at 18:00; the rock has had approximately 18 hours to dry but overnight humidity peaked at 93% near freezing, so condensation or thin ice may coat the north-facing surface.
Strong westerly winds yesterday (up to 56 km/h) would have efficiently stripped surface moisture from the exposed dolerite, and today's dry forecast with moderate southerly winds should continue drying, though the north aspect limits solar assistance.
Whin Sill dolerite does not suffer structural weakening when wet, but recent freeze-thaw cycles (overnight lows as low as -3°C in the past two weeks) increase the risk of loose blocks, particularly at the crag base.
Early April at 260m is still within the vulnerable spring window — short days, low sun angles on the north face, and overnight frosts mean conditions can be marginal even on nominally dry days.
Contributing Factors
6
Only 1.7mm fell yesterday in scattered light showers, a trivial amount for non-porous dolerite that sheds water readily.
Humidity rose to 93% overnight with temperatures dropping to -0.4°C, creating conditions for condensation or thin frost glaze on the cold north-facing rock.
Yesterday's powerful winds (up to 56 km/h) and today's moderate southerly breeze will have efficiently stripped surface moisture from the exposed escarpment.
The north aspect receives minimal direct sunlight in early April, so any frost or condensation will linger much longer than on a south-facing crag.
Whin Sill dolerite absorbs virtually no moisture, so drying is purely a surface phenomenon and occurs within hours of rain stopping.
Early April is prime peregrine nesting season and Crag Lough is a known nesting site; restrictions may close all or part of the crag.
Recommendations
3
- Check BMC Regional Access Database for peregrine nesting restrictions before making the journey — sections of the crag are very likely closed.
- Arrive later in the day (afternoon) to allow any overnight frost or condensation to dissipate from the north-facing rock, and test friction carefully on lower holds before committing.
- Be vigilant for loose blocks at the crag base — recent freeze-thaw cycles with lows down to -3°C may have loosened material.
Do Not Climb
40%
9 days ago
Crag Lough has received 1.4mm of rain today with very high winds (56 km/h), following a persistently wet period with nearly 100mm over the last 28 days. While the non-porous dolerite sheds water quickly, the rock is likely still damp from today's precipitation and the north-facing aspect limits any drying; conditions are not suitable right now but should improve markedly tomorrow.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Crag Lough is a peregrine nesting site — it is early April and nesting restrictions may be in force; check BMC RAD before visiting as access to some buttresses may be closed.
- The north-facing aspect at 260m means the crag receives virtually no direct sun at this time of year, so surface moisture relies entirely on wind-drying rather than solar evaporation.
- The exposed Whin Sill ridge catches strong westerly and south-westerly winds which significantly accelerate surface drying on this non-porous rock — today's 56 km/h gusts will strip surface water quickly once rain stops.
- Loose blocks at the crag base are common due to active freeze-thaw; with overnight lows dropping to -2.5°C tonight, fresh rockfall debris is possible at the base of the buttresses tomorrow morning.
Warnings
2
- Peregrine nesting restrictions are very likely active at Crag Lough in April — climbing on restricted buttresses risks permanent access withdrawal at this Hadrian's Wall heritage site.
- Overnight frost (-2.5°C) following saturated conditions increases the risk of loose block detachment; take extra care at the crag base and on approach.
Reasoning
Today's 1.4mm of rain means the rock surface is currently wet or damp, compounded by 84% average humidity over the past week and a saturated surrounding environment from 98mm in 28 days.
The extremely strong westerly winds (56 km/h today) will dry non-porous dolerite surfaces rapidly once precipitation ceases — likely within a few hours — but the north-facing aspect provides no solar assistance, and high ambient humidity may slow complete drying of seepage zones.
Dolerite does not weaken when wet, but overnight frost tonight (-2.5°C forecast) following recent saturation could trigger freeze-thaw block detachment at the crag base.
Early spring at 260m means short days, cool temperatures, and persistent dampness; peregrine nesting restrictions are likely active and must be checked before any visit.
Contributing Factors
7
1.4mm of precipitation today means the rock surface is currently wet or recently wetted.
56 km/h westerly winds on this fully exposed ridge will strip surface moisture from the non-porous dolerite rapidly once rain stops.
The north aspect receives negligible direct sunlight in early April, removing solar drying entirely and leaving wind as the sole drying mechanism.
Whin Sill dolerite does not absorb moisture and sheds surface water quickly, meaning extended drying periods are unnecessary.
98mm over 28 days with 84% average humidity means the surrounding ground, cracks, and seepage lines are thoroughly saturated.
Tonight's forecast low of -2.5°C following wet conditions creates freeze-thaw risk, potentially loosening blocks at the crag base.
April is peak peregrine nesting season and Crag Lough is a known nesting site; access restrictions may be in force.
Recommendations
3
- Check the BMC Regional Access Database for peregrine nesting restrictions at Crag Lough before planning any visit — several buttresses may be closed.
- If visiting tomorrow (April 6), arrive after mid-morning to allow overnight frost to thaw and the strong winds to finish drying any residual surface moisture.
- Be vigilant for fresh rockfall debris at the base of buttresses following tonight's freeze-thaw cycle, and avoid routes with known seepage lines until a longer dry spell.
Do Not Climb
45%
10 days ago
Crag Lough has received 3.3mm of rain today with very high winds, and the past week has seen frequent precipitation totalling nearly 17mm — the north-facing dolerite will be wet and extremely slippery right now. While the non-porous rock won't suffer structural damage, today's active rain and strong winds make climbing inadvisable on safety grounds.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Crag Lough is a peregrine nesting site — check BMC RAD for current seasonal restrictions before visiting, as nesting restrictions typically apply February–June.
- The north-facing aspect at 260m receives almost no direct sun in early spring, meaning surface moisture from rain and condensation lingers far longer than on south-facing crags.
- The crag sits on an exposed high ridge along Hadrian's Wall where strong SW/W winds are funnelled along the escarpment — while this aids surface drying of the non-porous rock, it makes conditions very hostile for climbing in high winds like today's 52+ km/h gusts.
- Loose blocks at the crag base are actively affected by freeze-thaw at this altitude in early April, with several recent nights dropping below zero — extra vigilance needed around detached blocks.
Warnings
3
- Today's winds exceeding 50 km/h on the exposed ridge make climbing dangerous regardless of rock moisture — risk of being blown off balance.
- Peregrine nesting restrictions may currently be in force at Crag Lough — climbing could be prohibited; verify before visiting.
- Active freeze-thaw at the crag base means loose blocks are a serious hazard — avoid lingering beneath the crag and wear a helmet at all times.
Reasoning
The rock is currently wet from today's 3.3mm of rain, compounded by 2.8mm yesterday and persistent precipitation through the past week, with humidity at 83% — surface water will be present on the dense dolerite.
The extreme wind exposure (52.6 km/h SW today) would normally dry non-porous dolerite within hours, but ongoing precipitation today means drying hasn't begun yet and won't start until rain ceases.
Whin Sill dolerite is non-porous and does not weaken when wet, but loose blocks at the crag base are a concern given recent freeze-thaw cycles with several nights dropping below zero in the past fortnight.
Early April at 260m on a north-facing aspect means minimal solar heating, short effective drying windows, and the tail end of freeze-thaw risk — combined with likely peregrine nesting restrictions, this is a marginal time of year for this venue.
Contributing Factors
7
3.3mm of precipitation today means the rock surface is currently wet and the dense black dolerite will be extremely slippery.
Winds of 52.6 km/h along the exposed Whin Sill ridge create dangerous conditions for climbing, despite aiding surface drying.
16.8mm over the last 7 days with no consecutive dry days means the crag environment is saturated, with water running in seepage lines and pooling at the base.
Whin Sill dolerite does not absorb water and will dry rapidly once precipitation stops and wind continues.
The north-facing orientation receives negligible direct sun in early April, slowing evaporation of surface moisture and any lingering dampness in cracks.
Recent nights dropping below zero at 260m altitude mean active freeze-thaw continues, increasing the hazard from loose blocks at the crag base.
Average humidity of 85% over the past week inhibits evaporation and encourages condensation on the cold north-facing rock surface.
Recommendations
3
- Wait for the drier spell forecast from April 6–8, when two consecutive dry days with lower humidity (70–71%) and moderate winds should leave the dolerite surface dry and climbable.
- Check the BMC Regional Access Database for current peregrine nesting restrictions at Crag Lough before planning any visit — spring restrictions are likely in effect.
- If visiting later this week, test friction on the rock surface before committing to any route, as north-facing dolerite can retain a greasy film even when it appears dry.
Do Not Climb
45%
11 days ago
Crag Lough received 3.6mm of rain today with high humidity (87%) and strong SW winds; the north-facing dolerite will be wet and slippery right now. While the non-porous rock dries quickly, zero consecutive dry days and persistent dampness over the past week make today unsuitable for climbing.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Crag Lough is a peregrine nesting site — it is currently spring (April) and bird nesting restrictions may be in effect; check BMC RAD for specific buttress closures before visiting.
- The north-facing aspect means the crag receives virtually no direct sun at this time of year, so surface moisture from today's rain will linger longer than on south-facing dolerite.
- The exposed ridge position along Hadrian's Wall means strong SW/W winds will help strip surface moisture relatively quickly, but today's rain is too recent for adequate drying.
- Active freeze-thaw is still a concern at 260m in early April — overnight lows near or below 0°C have been frequent, and loose blocks at the crag base pose a hazard.
Warnings
3
- Peregrine falcons nest at Crag Lough in spring — some buttresses may be closed; check BMC RAD before visiting.
- Active freeze-thaw at 260m with sub-zero overnight lows makes loose blocks at the crag base a serious hazard — wear a helmet and be vigilant.
- Crag Lough sits within the Hadrian's Wall UNESCO World Heritage Site — respect all access restrictions and leave no trace.
Reasoning
With 3.6mm of rain today, high humidity at 87%, and no consecutive dry days, the rock surface is almost certainly wet or at least damp right now.
Strong SW winds at 32.8 km/h will help strip surface moisture from this exposed crag, but the north-facing aspect and lack of direct sun mean drying will be slow despite the wind, and today's rain has not had time to clear.
Dolerite does not suffer structural weakening when wet, but active freeze-thaw at crag bases with overnight lows near 0°C means loose blocks remain a genuine hazard in early April.
Early spring at 260m brings unpredictable conditions with overnight frosts still possible, high background humidity, and critically, potential peregrine nesting restrictions that must be checked before any visit.
Contributing Factors
8
The crag received measurable rain today, meaning the rock surface is currently wet and slippery.
There has been no full dry day since the last rain, giving the rock no sustained drying window.
Humidity at 87% significantly retards evaporation and keeps surface moisture lingering on the rock.
The north-facing orientation receives minimal direct sunlight in early April, slowing drying considerably.
The exposed ridge position and strong SW winds will help strip surface moisture once rain stops.
Whin Sill dolerite does not absorb water, so once surface moisture evaporates, the rock is climbable — no extended drying time needed.
Nearly 15mm over the past week means persistent dampness in cracks, seepage lines, and at the crag base.
Overnight lows near or below 0°C in the forecast increase freeze-thaw hazard and the risk of loose blocks at the crag base.
Recommendations
3
- Do not climb today — the rock is wet from today's rain and will be dangerously slippery on this dense dolerite.
- Check BMC Regional Access Database for peregrine nesting restrictions at Crag Lough before planning any visit this spring.
- Consider targeting April 6th or 7th, when the forecast shows consecutive dry days, dropping humidity, and some wind to dry the crag — but visually assess on arrival.
Climbing Outlook