Condition Analysis
AI-powered assessment using site data and 14-day weather history
Five consecutive dry days with strong westerly winds have thoroughly dried the non-porous dolerite surface at Crag Lough. Conditions today are good for climbing, with the rock well-aired despite the north-facing aspect.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- The north-facing aspect means the dense black dolerite relies almost entirely on wind exposure for drying rather than direct sun, but five dry days with persistent westerly winds have been highly effective.
- Peregrine falcons nest here in spring — by mid-August restrictions should be lifted, but always check the BMC RAD for the current status before visiting.
- Crag Lough sits on Hadrian's Wall, a UNESCO World Heritage Site; climbers should stay on established approach paths and avoid disturbing any archaeological features.
- Seepage from the boggy ground above the crag can persist on certain lines even in dry spells — check for dark wet streaks on the rock face before committing to a route.
Warnings
2
- Loose blocks at the crag base are an ever-present hazard — wear a helmet on approach and belay.
- Verify peregrine nesting restrictions are lifted before climbing; check the BMC RAD for current seasonal closures.
Reasoning
The last significant rain was 4.0mm on 2026-08-09, five days ago, and the non-porous dolerite surface will have shed that moisture within hours given the exposed ridgeline position.
Persistent westerly winds averaging 17–25 km/h over the past five days have provided excellent air movement across the exposed crag, more than compensating for the north-facing aspect's lack of direct sun.
Whin Sill dolerite does not suffer structural weakening when wet, so hold breakage from moisture is not a concern — though inherently loose blocks at the crag base remain a perennial hazard.
Mid-August is peak summer season with long days and warm temperatures; freeze-thaw is not a factor and conditions are generally favourable for dolerite climbing.
Contributing Factors
5
No meaningful precipitation since 4.0mm on August 9th, giving ample drying time even for a north-facing crag.
Westerly winds of 16–25 km/h over the drying period have efficiently evaporated any residual surface moisture from the exposed ridgeline.
The lack of direct sun slows drying compared to south-facing crags, but five windy dry days more than compensate for non-porous rock.
Today's 87% humidity may create a slight film of condensation on the dense rock surface, marginally reducing friction.
Rain returns from August 16th onward with 3.7mm and 7.7mm on the 17th and 18th, meaning today's window is the best opportunity this week.
Recommendations
3
- Climb today or tomorrow for the best conditions this week — rain returns from August 16th and builds through the 18th.
- Check for localised seepage streaks from the boggy ground above before starting any route, as these can persist even during dry spells.
- Carry a towel and be prepared for slightly reduced friction on the dense dolerite if humidity is high, especially on slabby or smeared sections.
Previous Analyses
Likely Safe to Climb
88%
2 days ago
Crag Lough's dolerite has had four consecutive dry days following scattered light rain, with today forecast completely dry and warm — the non-porous rock will be thoroughly dry. Conditions are excellent for climbing today, particularly through the afternoon when humidity is low and wind moderate.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- The north-facing aspect means the crag receives no direct sunlight, but the exposed ridge position and consistent westerly winds have provided effective drying over the past four dry days.
- Peregrine falcons nest here in spring — check BMC RAD for any residual seasonal restrictions before visiting, though by mid-August nesting season should be over.
- Loose blocks and rockfall from freeze-thaw weathering at the crag base are a perennial hazard at Crag Lough; helmets are essential even in summer.
- The crag sits on Hadrian's Wall — a UNESCO World Heritage Site — so climbers should stay on established approach paths and avoid disturbing the scheduled monument.
Warnings
1
- Evening condensation is likely after 20:00 as humidity exceeds 84% — retreat before dusk to avoid slippery dolerite.
Reasoning
Four consecutive dry days on non-porous dolerite, with today reaching 27°C and humidity dropping to 49% by midday, means the rock surface will be fully dry.
Persistent westerly winds at 16–25 km/h over the exposed ridge have efficiently stripped surface moisture despite the north-facing aspect; the last significant rain (4.0 mm on Aug 9) is well within dolerite's rapid drying window.
Whin Sill dolerite does not weaken when wet and summer conditions pose no freeze-thaw risk, though loose blocks from prior freeze-thaw cycles remain a constant hazard at the crag base.
Mid-August provides long daylight hours and warm temperatures ideal for this exposed 260m venue; peregrine nesting restrictions should have lifted by now.
Contributing Factors
6
No meaningful precipitation since August 9 (4.0 mm), giving non-porous dolerite ample time to shed all surface moisture.
Today is forecast completely dry with a high of 27°C and afternoon humidity as low as 49%, ensuring excellent friction on the rock.
Consistent winds of 16–25 km/h from the west over recent days have accelerated surface drying on this highly exposed crag.
The lack of direct sunlight slows drying compared to south-facing crags, but after four dry days with wind this is inconsequential for non-porous rock.
Humidity rises sharply after 8pm (84–96%), which could cause condensation on the cold dolerite surface late in the evening.
A trace of rain (0.5 mm) is forecast for August 14, which is trivial for dolerite but signals a wetter pattern returning.
Recommendations
3
- Climb today during the optimal window of roughly 10:00–19:00 when humidity is lowest and temperatures warmest.
- Wear a helmet — loose blocks from freeze-thaw weathering at the crag base are a persistent hazard regardless of season.
- Check the BMC RAD for any remaining peregrine nesting restrictions before your visit, though these typically lift by mid-August.
Likely Safe to Climb
85%
3 days ago
Three consecutive dry days with moderate wind on non-porous dolerite mean the rock surface should be well dried; today's warm, low-humidity afternoon offers excellent conditions. The recent wet spell has fully cleared and the rock does not retain moisture internally.
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 in summer it can feel cold and windy — thermals and a windproof layer are advisable.
- Peregrine falcons nest here in spring; check BMC RAD for any lingering seasonal restrictions before visiting, though by mid-August these are typically lifted.
- The crag sits above Crag Lough lake and seepage from boggy ground above Hadrian's Wall can create persistent damp bands on certain buttresses even when the main faces are dry.
- Loose blocks and debris at the crag base are a year-round hazard, exacerbated by the recent wet period — helmets essential for belayers and seconds.
Warnings
2
- Loose blocks at the crag base are a standing hazard — helmets essential for all party members.
- Check BMC RAD for any active peregrine nesting restrictions before visiting.
Reasoning
Three full dry days since the last trace precipitation (0.0mm on Aug 10–12) following 4.0mm on Aug 9, combined with today's low humidity (48–55% at midday) and moderate wind, mean surface moisture on this non-porous dolerite should be fully evaporated.
The exposed, wind-swept ridge position ensures rapid surface drying even on north-facing rock; 3 days without meaningful rain and sustained 15–25 km/h winds are more than adequate for dolerite.
Dolerite does not weaken when wet so structural risk from the recent rainfall is negligible, though loose blocks at the base — a known Whin Sill characteristic — remain a standing hazard.
Mid-August provides long daylight hours and the warmest ambient temperatures of the year, both of which aid drying and extend the climbing window; freeze-thaw is not a concern at this time.
Contributing Factors
6
No significant precipitation since Aug 9 (4.0mm), with only trace amounts on Aug 10, giving dolerite ample time to shed all surface moisture.
Whin Sill dolerite does not absorb water, so drying is purely a surface process that completes within hours of rain stopping.
Today's peak of 25.5°C with humidity dropping to 48% creates ideal evaporative conditions for any residual dampness.
Sustained winds of 15–18 km/h across the open Whin Sill ridge accelerate surface drying significantly.
The north-facing orientation receives minimal direct sun, so shaded recesses and seepage bands may retain dampness longer than south-facing crags.
12.5mm fell in the last 7 days and 42.5mm in 28 days, but the 3-day dry window and non-porous rock mean this is no longer a significant concern.
Recommendations
3
- Climb this afternoon for the best conditions — humidity is at its lowest (48%) and temperatures peak around 15:00–17:00.
- Inspect shaded recesses and seepage bands at the base of buttresses before committing, as north-facing sheltered areas may hold residual dampness.
- Wear a helmet at the crag base due to loose blocks, and take care on the approach across boggy ground above the Wall.
Marginal — Assess Conditions
72%
5 days ago
The last significant rain was 4.0mm yesterday (Aug 9), and today is dry with moderate winds, but overnight humidity hit 100% suggesting dew or mist on the crag this morning. By mid-afternoon the rock should be surface-dry given dolerite's non-porous nature and the exposed, windy ridge, but climbers should check for residual dampness — especially on the north-facing holds which won't see direct sun.
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, meaning overnight dew and mist can linger well into mid-morning even in summer — the rock won't get meaningful direct sunlight to burn off moisture.
- The recent wet spell (27.4mm in 7 days) will keep seepage lines active where water drains through joints and cracks in the Whin Sill escarpment, even though the dolerite itself doesn't absorb water.
- Peregrine falcons nest here in spring — by August restrictions should be lifted, but always check the BMC RAD for current status before visiting.
- The crag sits on Hadrian's Wall — a UNESCO World Heritage Site — so tread carefully on the approach and avoid disturbing archaeology or the wall itself.
Warnings
2
- Dolerite becomes extremely slippery when damp — a thin moisture film invisible on the dark rock can cause sudden friction loss.
- Loose blocks at the crag base are a persistent hazard; test holds carefully and wear a helmet.
Reasoning
Dolerite is non-porous so yesterday's 4.0mm rain won't have soaked in, but overnight humidity reached 100% with full cloud cover, meaning dew and condensation will coat the rock surface this morning.
The exposed ridge and moderate westerly winds (14–17 km/h) will strip surface moisture through the afternoon, and humidity drops to ~57% by 15:00–16:00, so dolerite surfaces should be dry by early-to-mid afternoon.
Whin Sill dolerite does not weaken when wet, but loose blocks at the crag base remain a perennial hazard — no freeze-thaw concern in August.
Mid-summer conditions are generally favourable with long daylight hours, though the recent unsettled spell with frequent showers has kept background humidity high.
Contributing Factors
7
4.0mm fell on Aug 9 and only one full dry day has elapsed, though dolerite sheds surface water rapidly.
Humidity reached 100% from 04:00–07:00 with full cloud cover, likely depositing condensation on the cold north-facing rock.
Whin Sill dolerite does not absorb moisture, so only surface water needs to evaporate, which happens within hours under wind.
Consistent 12–17 km/h winds across the exposed escarpment accelerate surface drying significantly.
Humidity falls from 100% overnight to around 57% by mid-afternoon, favouring dry friction on rock surfaces.
The crag receives no direct sunlight, so solar warming won't assist drying and the rock remains cooler and slower to dry than south-facing crags.
27.4mm over the past 7 days will sustain seepage lines through joints in the escarpment even though the rock itself is non-porous.
Recommendations
3
- Wait until early-to-mid afternoon (after 13:00) before climbing today, allowing morning dew and condensation to clear from the north-facing rock.
- Test friction carefully on the first few moves — dolerite is notoriously slippery when even slightly damp, and the dark rock can look dry while retaining a thin moisture film.
- Avoid routes with obvious seepage lines or drainage cracks, as these may stay wet for days after the recent unsettled spell.
Do Not Climb
55%
5 days ago
Today saw 6.1mm of rain with high humidity (88%), and the crag is currently wet. Although dolerite is non-porous and dries quickly, the north-facing aspect, elevated humidity, and lack of direct sun mean residual surface moisture and seepage from the saturated ground above will persist into tomorrow morning.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- The north-facing aspect receives virtually no direct sunlight in summer, so drying relies almost entirely on wind exposure — today's westerly at 25 km/h helps but humidity at 88% limits evaporation.
- The crag sits below Hadrian's Wall and grazing land on the ridge top; after the very wet recent period (30mm in 7 days), ground saturation above will feed seepage lines down the cliff face for a day or more.
- Peregrine falcons nest here in spring — by August nesting restrictions should have lifted, but climbers should check the BMC RAD for any extended closures on specific buttresses.
- Loose blocks and freeze-thaw debris accumulate at the crag base; the recent wet spell may have loosened material, so helmets are essential and care should be taken on approach ledges.
Warnings
2
- Dolerite is extremely slippery when wet — even a thin moisture film drastically reduces friction on the dense black rock.
- Ground saturation from 30mm of rain in the past week means seepage lines may persist on the face even after the rock surface appears dry.
Reasoning
6.1mm of rain fell today on top of a very wet week (30mm in 7 days), and with 88% humidity the rock surface and surrounding ground are thoroughly saturated.
Exposed westerly winds at 25 km/h will strip surface moisture from the dolerite relatively quickly, but the north-facing aspect receives no direct sun and the high humidity severely limits evaporative drying — expect the rock to remain damp into tomorrow morning.
Dolerite does not weaken when wet, but the dense black surface becomes extremely slippery; loose blocks at the crag base may have been destabilised by the prolonged wet period.
Mid-summer provides the longest drying days and warmest temperatures, though the recent unsettled Atlantic pattern has kept conditions cool and humid for the altitude.
Contributing Factors
7
6.1mm of rain today means the rock is currently wet with no dry hours accumulated.
Over 30mm in the last 7 days has saturated the ground above the crag, feeding seepage lines across the face.
Near-saturated air significantly slows evaporative drying on the already-wet rock surface.
No direct sunlight reaches the face, removing the most effective drying mechanism for surface moisture.
Westerly winds at 25 km/h provide meaningful air movement across the face, which will assist surface drying once rain stops.
Whin Sill dolerite does not absorb water, so only surface moisture needs to evaporate — no multi-day drying requirement.
No rain forecast for August 10th, with humidity dropping to 82% and continued moderate wind, allowing progressive drying.
Recommendations
3
- Wait until at least tomorrow afternoon to allow the rock surface to dry fully after today's 6.1mm of rain — dolerite dries fast but seepage from saturated ground above may linger.
- Check seepage lines and drainage gullies on arrival; the lower-angle slabs and cracks will hold moisture longest on this north-facing crag.
- Wear a helmet on the approach and at the crag base — the prolonged wet spell may have loosened blocks, especially at freeze-thaw-prone ledges.
Do Not Climb
45%
6 days ago
The crag has seen significant rainfall over the past week (24mm in 7 days), including 6.6mm yesterday and light precipitation today, with high humidity averaging 83%. Although dolerite is non-porous and dries quickly in theory, the north-facing aspect, persistent dampness, and forecast rain tomorrow (4.5mm) make today a poor choice — surfaces are very likely still wet and slippery.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- The north-facing aspect at 260m receives almost no direct sun in any season, meaning surface moisture from rain, condensation, and seepage from the grassy slopes above lingers far longer than on sun-facing dolerite.
- Crag Lough sits on the Whin Sill escarpment where the exposed ridge funnels westerly winds across the face — this aids drying but also means wind chill and gusts can be significant, affecting belayer comfort and rope management.
- Peregrine falcons nest here in spring; although August is outside the core nesting restriction window, birds may still be present and climbers should check BMC RAD for any residual voluntary restrictions.
- Active freeze-thaw loosens blocks at the crag base — after a wet spell like the past week, loose material may have shifted, so extra care is needed on approach and at the base of routes.
Warnings
2
- Dolerite is extremely slippery when wet — a fall due to friction loss is the primary risk; do not climb if any surface moisture is visible.
- Loose blocks at the crag base may have shifted during the recent wet spell — wear helmets and assess the base carefully before setting up.
Reasoning
With 6.6mm on Aug 7, 0.2mm today, and 24mm over the past week at 83% average humidity, the dense dolerite surfaces are very likely still carrying a film of moisture, especially on the north-facing, shaded rock.
The exposed position and moderate westerly winds (25–37 km/h recently) help strip surface water relatively quickly, but the north-facing aspect and persistent high humidity have severely limited evaporative drying since the last significant rain yesterday.
Dolerite does not suffer structural weakening when wet, but the recent prolonged wet spell may have accelerated freeze-thaw loosening of already detached blocks at the crag base — a physical hazard rather than a rock-quality concern.
Mid-summer provides the longest drying windows and warmest temperatures, but this has been an unusually wet and cool spell for August, with temperatures well below seasonal norms and humidity consistently above 80%.
Contributing Factors
6
24.2mm in the past 7 days including 6.6mm yesterday means the rock has had very little time to dry, despite dolerite's non-porous nature.
The north-facing orientation receives negligible direct sunlight, dramatically slowing evaporation of surface moisture.
Average humidity of 83% over the past week inhibits evaporation and may cause condensation on the cold rock surface.
Sustained winds of 25–37 km/h across the exposed ridge help strip surface water from the rock relatively quickly.
Whin Sill dolerite does not absorb water so only surface moisture needs to evaporate, allowing much faster drying than sandstone.
4.5mm forecast for Aug 9 will re-wet any surfaces that manage to dry today, extending the problematic window.
Recommendations
3
- Wait until August 10 at the earliest, when a dry spell with lower humidity and lighter winds is forecast to begin, allowing the rock to dry properly.
- If visiting on Aug 10 or later, check for residual seepage from the grassy slopes above the crag — water can weep down the face long after the rock itself has dried.
- Bring a towel and chalk for any residual damp patches, and test friction carefully on the first few moves before committing to any route.
Do Not Climb
55%
7 days ago
Crag Lough has received 4.2mm of rain today on top of a very wet week (22mm in 7 days), and although dolerite is non-porous and dries quickly, the north-facing aspect, high humidity (85% average), and persistent dampness mean the rock surface is almost certainly wet and dangerously slippery right now. Tomorrow looks promising with a dry forecast and moderate winds, but today climbing is inadvisable.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- The north-facing aspect receives virtually no direct sun in summer, so surface moisture relies almost entirely on wind and ambient warmth to evaporate — drying is slower than at south-facing dolerite crags.
- Seepage from the grassy ridge top above the crag can persist for days after heavy rain, creating wet streaks down the face even when the rock itself has shed surface water.
- Peregrine falcons nest here in spring; check BMC RAD for any remaining seasonal restrictions before visiting in early August.
- The exposed ridgeline position means strong westerly winds (25–37 km/h recently) help strip surface moisture quickly, but also create challenging conditions for climbing on this exposed face.
Warnings
2
- The rock is currently wet from today's rain and will be extremely slippery — dolerite offers almost zero friction when damp.
- Persistent seepage from saturated ground above the crag may affect routes even after the rock face appears dry.
Reasoning
Today's 4.2mm of rain, following 22mm in the past week with humidity averaging 85%, means the rock surface is currently wet and likely has standing water in cracks and on ledges.
Although dolerite sheds surface water rapidly and the exposed position with 25+ km/h westerly winds aids drying, the north-facing aspect receives negligible direct sun, so drying depends entirely on wind evaporation — expect several hours of drying needed after rain stops.
Dolerite does not weaken when wet, but loose blocks at the crag base are a persistent hazard exacerbated by winter freeze-thaw cycles; no elevated structural risk in current summer conditions.
Mid-summer provides the longest drying windows and warmest temperatures, but the recent spell of unsettled Atlantic weather has kept conditions persistently damp with above-average humidity.
Contributing Factors
6
4.2mm today following 10.5mm on Aug 4, 4.4mm on Aug 5, and 1.9mm on Aug 6 means the crag has had no meaningful dry spell in four days.
Average humidity of 85% over the last week significantly slows evaporation from the rock surface, even with wind assistance.
The north-facing orientation receives essentially no direct sunlight, removing the most effective drying mechanism and leaving wind as the sole driver.
Consistent 25–37 km/h winds over recent days help strip surface moisture from the non-porous dolerite much faster than at sheltered crags.
Dolerite does not absorb water, so once surface moisture evaporates the rock is immediately climbable — no internal drying period required.
Temperatures around 15–20°C provide reasonable evaporation potential despite the lack of direct sun on this aspect.
Recommendations
3
- Wait for tomorrow (Aug 8) which is forecast dry with moderate SW winds — allow a few hours into the day for any residual dampness to clear before climbing.
- On arrival, test friction on lower holds before committing to routes; dolerite gives almost no warning before becoming dangerously slick.
- Watch for seepage lines from the grassy ridge above, which may persist even when the main face appears dry — avoid routes beneath obvious drainage channels.
Marginal — Assess Conditions
62%
9 days ago
Light rain fell overnight and through the early morning, but the rock is non-porous dolerite and the exposed, windy ridge should allow surface drying by early-to-mid afternoon. A dry window from around 12:00–19:00 today looks plausible, but climbers should visually confirm the rock is dry and grippy before committing, especially on the north-facing surfaces that won't benefit from direct sun.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- The north-facing aspect means the crag receives virtually no direct sunlight, so surface drying relies almost entirely on wind and ambient temperature — even in summer the rock can remain damp longer than expected.
- Crag Lough sits on the exposed Whin Sill ridge and today's westerly winds of 15–19 km/h through the afternoon will be the primary drying mechanism, which is helpful.
- Seepage from the saturated ground above the crag (31.5 mm over 28 days with repeated wet spells) may produce persistent weeps on certain lines, particularly where vegetation sits above buttresses.
- Peregrine falcon nesting restrictions may still apply into late summer — check BMC RAD for current status before visiting.
Warnings
2
- Dolerite is extremely slippery when damp — if the rock doesn't feel grippy to the touch, do not climb.
- Loose blocks at crag bases are an ever-present hazard; test holds carefully and wear a helmet.
Reasoning
Light overnight drizzle (roughly 1 mm total) on top of a recent wet spell means the rock surface is currently damp, though dolerite's non-porous nature means no internal absorption has occurred.
Persistent westerly wind at 15–19 km/h and falling humidity (down to 56% by mid-afternoon) should strip surface moisture from the exposed ridge within a few hours of rain ceasing around 07:00, but the north-facing aspect provides no solar assistance.
Dolerite does not weaken when wet, but loose blocks at the crag base remain a hazard — recent freeze-thaw is unlikely in August, though the active wet spell may have loosened soil around perched blocks.
Mid-summer provides the longest drying days and warmest temperatures, though August 2026 has been notably cool and wet at this altitude (average 13.3°C over the past week with 17 mm of rain).
Contributing Factors
7
Approximately 1.1 mm of precipitation fell today, mostly overnight into early morning, leaving surface moisture on the rock.
Whin Sill dolerite does not absorb water, so only surface moisture needs to evaporate — typically achievable within hours.
Sustained westerly winds of 15–19 km/h through the afternoon will actively strip surface moisture from the rock.
The crag receives no direct sunlight, removing solar heating as a drying factor and relying entirely on wind and ambient conditions.
Humidity is forecast to fall to 56–58% between 14:00–17:00, which favours rapid surface evaporation on exposed rock.
Over 17 mm fell in the past 7 days and 31.5 mm over 28 days, saturating the ground above the crag and increasing seepage risk on some lines.
11.1 mm is forecast for 7 August, meaning today's afternoon window may be the only opportunity before another significant wetting.
Recommendations
3
- Target the afternoon window (approximately 13:00–18:00) when humidity drops below 60% and the wind has had several hours to dry the surface — visually and physically check friction before committing to routes.
- Avoid lines below vegetation or obvious seepage bands, as the saturated ground above may produce persistent weeps despite the rock itself being non-porous.
- Check the BMC RAD for any active peregrine nesting restrictions and be aware that tomorrow's heavy rain forecast may make the next good window several days away.
Do Not Climb
55%
11 days ago
Significant rain fell this morning (over 6mm today so far) and the rock will still be wet or damp through much of the afternoon; although dolerite dries quickly, the north-facing aspect, 100% cloud cover, and high humidity are slowing evaporation. Tomorrow brings even heavier rain (8.8mm forecast), so conditions are unlikely to improve in the short term.
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, meaning it receives virtually no direct sun and relies almost entirely on wind for drying — easterly or southeasterly winds today offer limited direct drying on the north face.
- The dense black dolerite becomes extremely slippery when wet, and with rain as recent as midday today, surface water films and residual dampness in cracks will persist into the afternoon despite the exposed position.
- Peregrine falcons nest here in spring; by August restrictions are typically lifted, but climbers should check the BMC RAD for any lingering seasonal closures.
- The crag sits within the Hadrian's Wall UNESCO World Heritage Site — access is permissive and sensitive; avoid disturbing the wall or surrounding archaeology.
Warnings
2
- Dolerite is treacherously slippery when wet — a surface that looks dry can still have a thin moisture film that dramatically reduces friction.
- Loose blocks and debris at the crag base are common; take extra care on approach and belay stances, especially after recent wet weather.
Reasoning
Rain fell through the early morning and again around midday (totalling ~6.4mm today), so the rock surface is currently wet or at best damp, with seepage likely in cracks and on ledges.
Although the exposed ridge position and moderate winds (~15–23 km/h) aid surface drying, the north-facing aspect receives no direct sun, humidity remains above 80%, and cloud cover is 100% — meaning surface drying will be slow and incomplete through the afternoon.
Dolerite is non-porous and does not suffer structural weakening when wet; the primary risk is friction loss on the slick, dense rock surface rather than hold breakage.
Summer conditions are generally favourable for drying, but the recent unsettled spell (nearly 10mm in the last 7 days and a wet forecast ahead) is keeping humidity persistently high at this altitude.
Contributing Factors
6
Over 6mm of precipitation fell today, with the last notable shower around midday, leaving the rock surface wet.
The crag receives no direct sunlight, relying entirely on wind and ambient warmth for drying.
Humidity has been 80–99% all day with 100% cloud cover, significantly retarding evaporation.
Moderate winds of 15–23 km/h on the exposed Whin Sill ridge help strip surface moisture, partially offsetting the lack of sun.
Whinstone does not absorb water, so once surface moisture evaporates the rock is climbable — no prolonged drying period needed.
8.8mm of rain is forecast for 5 August with 93% humidity and strong SW winds, meaning any brief drying today will be undone.
Recommendations
3
- Wait at least until the late afternoon dry window (16:00–20:00) if you insist on visiting today, and perform a careful touch-test on the rock before committing to any routes.
- Avoid Crag Lough tomorrow (5 August) entirely — heavy rain is forecast and conditions will be poor.
- The best window in the coming week looks to be 6 August afternoon, after overnight rain clears and humidity drops to ~69%; check conditions on arrival.
Marginal — Assess Conditions
65%
12 days ago
Light drizzle earlier this morning should dry quickly on the exposed, non-porous dolerite, and a dry window from roughly 08:00–21:00 with dropping humidity and moderate easterly winds offers a reasonable climbing opportunity this afternoon. However, overnight rain is forecast tonight and heavy rain (14.7 mm) arrives tomorrow, so climbers should visually confirm surfaces are dry and friction is adequate before committing.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Crag Lough is north-facing and receives virtually no direct sun, so any surface moisture from morning drizzle or overnight condensation relies entirely on wind for evaporation.
- The exposed high ridge position on Hadrian's Wall means moderate-to-strong winds (20–26 km/h easterly today) will assist drying significantly, partially compensating for the lack of sun.
- Loose blocks and active scree at the crag base are a persistent hazard — recent wet spells (9.2 mm in the past week) may have loosened material further.
- Peregrine falcons nest here in spring; by August nesting restrictions should have lifted, but always check current BMC RAD notices before visiting.
Warnings
3
- Dense black dolerite becomes extremely slippery when even slightly damp — what looks dry can still lack adequate friction, so test holds carefully.
- Rain returns late tonight (~22:00) and heavy rain (14.7 mm) is forecast tomorrow; do not be caught out by deteriorating conditions.
- Loose blocks at the crag base are an ongoing hazard — wear a helmet on approach and beware of rockfall from parties above.
Reasoning
Light scattered drizzle (0.1 mm/hr) fell between 04:00 and 07:00 this morning, and 0.3 mm fell yesterday — the non-porous dolerite surface will hold this as a thin film rather than absorbing it, so it should evaporate relatively quickly.
With moderate easterly winds (17–25 km/h) and humidity dropping to the low 60s by early afternoon, surface moisture from this morning's light drizzle should clear within a couple of hours despite the north-facing aspect receiving no direct sun.
Dolerite does not weaken when wet, but loose blocks at the crag base are an ongoing concern — the recent week of intermittent rain (9.2 mm) is unlikely to have caused new instability but vigilance is warranted.
Mid-summer conditions are generally favourable with long daylight hours and no freeze-thaw risk, though the unsettled Atlantic pattern bringing regular fronts means conditions can change quickly at this exposed 260 m altitude.
Contributing Factors
7
Whin Sill dolerite does not absorb water, so surface moisture from this morning's light drizzle will evaporate quickly rather than seeping in.
Light precipitation (0.4 mm total) fell between 04:00 and 07:00 this morning, leaving a thin moisture film on the rock surface.
From approximately 08:00 to 21:00 no rain is forecast, with humidity dropping to the low 60s and winds of 20–26 km/h assisting evaporation.
The crag receives no direct sunlight, meaning drying depends entirely on wind and ambient temperature rather than solar heating.
The high ridge location ensures consistent wind exposure (20+ km/h today), which is the primary drying mechanism for this north-facing crag.
14.7 mm of rain is forecast for 4 August, meaning today's afternoon window is the only viable opportunity before conditions deteriorate significantly.
The past week has seen 9.2 mm of scattered rain with average humidity of 81%, meaning background moisture levels in vegetation and seepage lines above the crag are elevated.
Recommendations
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- If climbing today, target the early-to-mid afternoon window (12:00–18:00) when humidity is lowest and winds are strongest, and physically touch-test rock surfaces for residual slipperiness before committing.
- Avoid the crag tomorrow (4 August) — 14.7 mm of heavy rain is forecast and conditions will be clearly unsuitable.
- Check the BMC RAD for any current access restrictions related to peregrine nesting or Hadrian's Wall heritage site management before visiting.
Climbing Outlook