Condition Analysis
AI-powered assessment using site data and 14-day weather history
Brimham Rocks has had an excellent drying window with only trace precipitation (0.1mm) in the last 7 days and 4 consecutive dry days including today's warm, breezy conditions. The rock should be thoroughly dry across all aspects, making today an ideal day to climb.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Brimham's exposed moorland position and consistent 20+ km/h westerly winds over the past week have significantly accelerated drying across all formations.
- The most recent meaningful rain was 3.7mm on Aug 4 (10 days ago) and 1.6mm on Aug 5 (9 days ago), both well within safe drying margins given the subsequent warm, breezy weather.
- North-facing sides of the towers and pinnacles will have dried more slowly, but even these should be fully dry after 9+ days of favourable conditions with only trace moisture since.
- Heavy rain is forecast for Aug 18 (10.3mm) — climbers planning visits later this week should be aware conditions will deteriorate significantly from Monday.
Reasoning
The last significant rain fell on Aug 4–5 (5.3mm total), followed by 9 days of predominantly dry, warm, and windy weather with only negligible trace amounts — the rock should be thoroughly dry internally and externally.
Sustained winds of 18–24 km/h combined with warm temperatures (up to 32°C on Aug 13) and moderate humidity (53–74%) have provided excellent evaporative drying conditions far exceeding the 48–72 hour guideline for light-to-moderate rain.
With extended drying and summer conditions, internal moisture levels should be well below any threshold for structural concern; the gritstone will be at or near full compressive strength.
Mid-August summer conditions are among the best of the year for gritstone climbing, with warm temperatures, long days, and no freeze-thaw risk.
Contributing Factors
5
Only 0.1mm of precipitation in the last 7 days, with 4 fully consecutive dry days and the last meaningful rain (5.3mm) falling 9–10 days ago.
Consistent winds of 18–26 km/h from westerly directions on the exposed moorland have greatly accelerated evaporation from all rock surfaces.
Temperatures reaching 24–32°C over the past few days have maximised evaporative drying potential across all aspects.
Average humidity of 64% over the past week is well below saturation, allowing effective net evaporation from the rock.
10.3mm of rain is forecast for Monday Aug 18, which will require a full drying cycle before climbing resumes safely.
Recommendations
3
- Conditions are excellent today and through the weekend — take advantage of the dry window before rain arrives on Monday.
- On Sunday (Aug 17), be aware that 2.3mm of rain is forecast and conditions may deteriorate through the afternoon; plan for an early session if climbing that day.
- After Monday's heavy rain (10.3mm forecast), allow at least 48–72 hours of dry weather before returning to climb.
Previous Analyses
Likely Safe to Climb
90%
2 days ago
Brimham Rocks is in excellent condition today. The last meaningful rain was 5.3mm across August 3–5 (8+ days ago), followed by a sustained dry spell with warm temperatures, low humidity, and consistent wind — more than sufficient drying time for gritstone even on north-facing aspects. Today's hot, dry conditions (32°C, humidity down to 24%) are ideal.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Brimham's scattered tower and pinnacle formations mean some sheltered recesses between boulders can hold dampness longer than the exposed faces, but 8+ dry days should have resolved this.
- North-facing aspects on the tors will have dried more slowly, but the sustained windy conditions (averaging 20+ km/h from the west) and warm summer temperatures provide ample compensation.
- The National Trust site has managed access and car parking; weekday visits are generally quieter, and the open moorland setting means wind chill can be significant even in summer.
- Some lower boulder bases and ground-level starts near vegetation or peat can retain moisture from the moorland — check the ground at the base of problems as a field test.
Warnings
1
- Extreme heat today (32°C) — carry plenty of water, take breaks in shade, and be alert to heat exhaustion on the exposed moorland.
Reasoning
The last significant precipitation was 3.7mm on Aug 4 and 1.6mm on Aug 5, over 8 days ago; only trace amounts (0.0–0.3mm) since then, meaning internal moisture has had ample time to evaporate.
Eight consecutive days of effectively dry weather with temperatures averaging 17–24°C, humidity 60–74%, and sustained winds of 15–23 km/h on an exposed moorland site provide excellent drying — well beyond the 48-hour guideline for light rain on gritstone.
With over a week of drying since the last light rain and no heavy saturation events in the preceding period, there is negligible risk of internal moisture weakening holds or grain structure.
Mid-August is peak summer season with long daylight hours, warm temperatures, and no freeze-thaw risk; today's 32°C heat may be the main concern for climber comfort rather than rock condition.
Contributing Factors
5
Over 8 days since the last meaningful rain (5.3mm total Aug 3–5), with only trace precipitation since, far exceeding the 48-hour minimum guideline.
Today's forecast peak of 32.8°C with humidity dropping to 24% creates exceptional evaporative conditions that ensure thorough surface and subsurface drying.
Brimham's exposed moorland position has received consistent winds of 15–25 km/h throughout the drying period, significantly accelerating moisture removal from the rock.
Only 9.1mm of precipitation over the past 28 days means the rock was never deeply saturated, reducing the drying time needed.
A substantial 32.4mm rainfall event is forecast for August 17, which will fully saturate the rock and require several days of drying afterwards.
Recommendations
3
- Conditions are excellent today and through the weekend — make the most of it before the heavy rain forecast for Monday August 17.
- Stay hydrated and consider sun protection; 32°C on exposed moorland with limited shade will be physically demanding.
- Be aware that after the 32mm rain forecast for August 17, Brimham will likely need 48–72 hours of dry weather before conditions are suitable again.
Likely Safe to Climb
88%
3 days ago
Brimham Rocks is in excellent condition for climbing today. The last meaningful rain was 3.7mm on August 4th (8 days ago), followed by only trace amounts; the exposed moorland position, warm temperatures, and steady winds have provided ample drying time across all aspects.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Brimham's scattered tower and pinnacle formations mean some sheltered alcoves between boulders can hold localised dampness longer than the exposed faces — check recessed cracks and chimneys at the base of formations.
- North-facing sides of individual towers (e.g. Cubic Block, Hawk Crag area) dry significantly slower than the south-facing aspects, but 8 days of dry weather should have resolved this.
- The National Trust car park has a pay-and-display charge and the site can get very busy with tourists in summer — early starts or weekday visits give better access to popular formations.
- Seepage can occur at the base of some formations where water drains through the moorland peat above, particularly after prolonged wet spells — less of a concern given the dry July/August pattern.
Reasoning
The last significant rainfall was 3.7mm on August 4th, eight days ago, with only negligible trace amounts (0.0–0.3mm) since; internal moisture levels should be very low across all faces.
Eight days of drying with consistent 15–25 km/h winds on an exposed moorland site at 290m, combined with mid-summer temperatures averaging 16–24°C and moderate humidity (62–75%), provide far more than the 48-hour minimum needed after light rain.
Structural risk is negligible given the extended dry period; the rock should be at or near full compressive strength with no meaningful internal moisture remaining.
Mid-August offers near-optimal conditions with long daylight hours, warm temperatures, and no freeze-thaw risk; today's forecast high of 29°C with humidity dropping to 28% is exceptional for gritstone friction.
Contributing Factors
6
Eight days since last meaningful rain (3.7mm on Aug 4), with only trace precipitation since, well exceeding the 48-hour guideline for light rain.
Temperatures have been consistently 16–24°C over the past week, with today reaching 29°C — excellent for evaporative drying.
Brimham's exposed moorland position has seen sustained winds of 15–27 km/h over the drying period, significantly accelerating moisture removal from the rock.
Average humidity of 67% over the past week is reasonable, and today's afternoon humidity drops below 35%, providing excellent evaporative potential.
With all aspects represented and an extended dry period, even the north-facing sides of formations should be fully dry by now.
A negligible 0.1mm on August 10th is essentially dew-level moisture and would evaporate within hours on exposed gritstone.
Recommendations
3
- Conditions are excellent — enjoy the full range of formations and aspects today, but still give a quick visual and touch check to any deeply recessed cracks or shaded chimneys before committing.
- Take advantage of the warm, dry afternoon (humidity as low as 28%) for friction-dependent slabs and delicate face routes.
- Be aware that rain is forecast from August 16th — plan any ambitious projects for the next three days while conditions remain ideal.
Likely Safe to Climb
88%
5 days ago
Brimham Rocks should be in excellent climbing condition today. The last meaningful rainfall was 5.6mm spread across Aug 3–5 (peaking at 3.7mm on Aug 4), and since then there have been 3+ full dry days with good wind exposure and moderate summer temperatures — more than adequate drying time for these amounts on exposed gritstone.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Brimham's scattered tower and pinnacle formations mean some north-facing recesses and sheltered gullies between boulders can hold moisture longer than the exposed south-facing faces — check these areas individually.
- The open moorland position at 290m means wind exposure is consistently high, which has been a major drying advantage over the past few days (22–26 km/h westerly winds).
- Some lower sections and bases of formations where moorland ground stays damp can wick moisture upward — check that the ground at the base of your chosen formation is dry before committing.
- National Trust managed site with seasonal access considerations — check car park opening times and any current NT restrictions before visiting.
Reasoning
The most significant recent rain was 3.7mm on Aug 4 and 1.6mm on Aug 5, with only a trace (0.3mm) on Aug 7; three fully dry days since with exposed windy conditions mean surface and internal moisture should be well dissipated.
Sustained westerly winds of 22–27 km/h over the past three days combined with moderate temperatures (16–24°C) and dropping humidity (down to 62–63%) on this exposed moorland site provide excellent drying conditions — comfortably exceeding the 48-hour guideline for light-to-moderate rain.
With adequate drying time elapsed and no prolonged saturation event, structural risk from weakened holds is minimal; the rock should have regained full compressive strength.
Mid-summer conditions are ideal — long days, warm temperatures, no freeze-thaw risk, and the rock has not been subject to prolonged winter saturation.
Contributing Factors
6
The last notable rainfall (3.7mm) was six days ago on Aug 4, with only trace amounts since, well exceeding the 48-hour minimum drying guideline.
Consistent winds of 19–27 km/h from westerly directions over the drying period have significantly accelerated evaporation on this already-exposed moorland site.
Temperatures of 16–24°C over the drying period provide good evaporative energy, with today forecast to reach 20°C.
Humidity is dropping through the day to 40–42% by mid-afternoon, indicating excellent surface drying conditions.
South and west-facing formations will be fully dry, while some sheltered north-facing recesses may retain slight residual dampness and should be checked.
Only 5.6mm total over the past 7 days and 9.0mm over the past 28 days represents an unusually dry spell, meaning the rock has not been deeply saturated.
Recommendations
3
- Conditions look good across most formations — south- and west-facing aspects should be fully dry and ready to climb.
- Check north-facing or deeply sheltered recesses between boulders by touch before climbing, as these may still hold trace dampness.
- Take advantage of the excellent dry forecast this week — conditions are set to remain ideal through at least Aug 15.
Marginal — Assess Conditions
75%
5 days ago
Brimham has had only 2 full dry days since the last notable rain on Aug 4–5 (5.3mm combined), with a trace of 0.3mm on Aug 7. Conditions are improving with good wind exposure and moderate summer temperatures, but south- and west-facing formations should be checked carefully — north-facing features may still hold residual moisture internally.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Brimham's scattered tower-and-pinnacle layout means each formation has its own micro-aspect; south-facing towers like Cubic Block will dry far faster than north-facing recesses around Lovers' Leap or the Dancing Bear area.
- The exposed moorland position at 290m provides excellent wind-assisted drying, which is the strongest factor in Brimham's favour right now — sustained 20–25 km/h westerlies have been blowing across the site.
- Seepage and dampness can linger at the base of the larger formations and in horizontal breaks/cracks, particularly on features surrounded by heather and peat which retain ground moisture.
- National Trust managed site — parking charges apply and the estate car park can fill quickly on summer weekends; early arrival recommended.
Warnings
1
- North-facing features and sheltered recesses may still be damp internally despite appearing dry on the surface — test carefully before committing.
Reasoning
The combined 5.3mm on Aug 4–5 plus a 0.3mm trace on Aug 7 means the rock has had only about 48 hours of uninterrupted drying, which is borderline for gritstone even in summer conditions.
Sustained westerly winds of 20–25 km/h and temperatures around 17–24°C on an exposed moorland site provide strong drying conditions, and the well-exposed formations should have shed most surface moisture — but internal drying of the porous gritstone may not be complete on all aspects.
With only moderate total rainfall (5.3mm significant, plus traces) and summer temperatures well above freezing, structural risk from strength loss is moderate rather than severe, but caution is warranted on north-facing or sheltered features.
Mid-summer conditions are broadly favourable with long days, warm temperatures, and no freeze-thaw concern; this is the best time of year for gritstone drying.
Contributing Factors
6
A total of 5.3mm fell across Aug 4–5 with high humidity (85–86%), providing enough moisture to penetrate the porous gritstone significantly.
An additional 0.3mm on Aug 7 partially reset the drying clock, leaving only 2 full dry days before today.
Sustained winds of 22–27 km/h from the west and southwest across the open moorland have significantly accelerated surface and near-surface drying.
Temperatures of 17–24°C with moderate humidity (62–75%) provide good evaporative potential for mid-altitude gritstone.
South- and west-facing formations will have dried well in the prevailing wind and sun, but north-facing features receive far less direct solar heating and will lag behind.
No rain is forecast for the next 6 days, meaning conditions will continue to improve steadily from tomorrow onward.
Recommendations
3
- Visually inspect rock surfaces and check for dampness in horizontal breaks and at the base of formations before committing to climb — if the ground beneath a feature is damp, the rock likely retains internal moisture.
- Favour south- and west-facing formations and upper sections of towers today; avoid north-facing recesses and low-level problems where moisture lingers longest.
- Conditions will improve markedly over the next 2–3 days with the continued dry, warm forecast — if in any doubt today, returning tomorrow or Tuesday offers much greater confidence.
Marginal — Assess Conditions
72%
6 days ago
Recent light rain on Aug 4–5 (5.3mm combined) and a trace on Aug 7 mean the rock has had limited drying time despite today's warm, dry, windy conditions. South- and west-facing formations are likely dry, but north-facing surfaces and sheltered recesses may still hold residual moisture — a visual check on arrival is advisable.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Brimham's scattered tower and pinnacle formations mean every face has a different aspect and wind exposure — south-facing open towers will be substantially drier than north-facing sheltered alcoves.
- The exposed moorland position and today's sustained SW wind (~21 km/h) significantly accelerate surface drying, making this site faster to recover than sheltered valley crags.
- Some formations have horizontal breaks and flat ledges that pool water; these seepage lines can feed moisture into the rock well after rain has stopped.
- National Trust site with permissive access — respect any seasonal path closures and avoid climbing on visibly damp rock to maintain the goodwill that keeps access open.
Warnings
2
- Do not climb on any formation that feels cool or dark-patched to the touch — gritstone can appear surface-dry while retaining damaging internal moisture.
- North-facing formations may still be damp internally despite today's good drying; treat these with extra caution.
Reasoning
The most significant rain was 3.7mm on Aug 4 and 1.6mm on Aug 5, with a trace (0.3mm) on Aug 7 — the rock has had only one fully dry day (today) since the last measurable precipitation, which is marginal for confident drying of porous gritstone.
Today's conditions are excellent for drying — 23.7°C, 60% humidity, sustained SW wind at 21 km/h — and should have removed surface moisture effectively on exposed south/west faces, but one day of good drying after ~5mm of rain in two days is at the lower bound of adequacy.
Summer temperatures eliminate freeze-thaw concerns; the primary structural risk is climbing on internally damp gritstone where grain cohesion is reduced, particularly on north-facing formations that have had less drying benefit.
Mid-summer conditions with long daylight hours and warm temperatures are broadly favourable, and the relatively low total rainfall (9mm over 28 days) means background saturation levels are low.
Contributing Factors
6
A combined 5.3mm fell on Aug 4–5 with only one full dry day since, which is below the recommended 24–48 hour minimum for light rain on porous rock.
0.3mm yesterday reset the surface moisture clock, though this amount alone is unlikely to penetrate deeply.
Warm temperatures (23.7°C), low humidity (60%), and sustained SW wind (21 km/h) on an exposed moorland site provide excellent evaporative drying today.
Only 9mm total over 28 days means the rock was not deeply saturated before the recent rain, so less internal moisture needs to escape.
South- and west-facing towers have benefited most from today's sun and SW wind, while north-facing and sheltered formations will be significantly slower to dry.
The open moorland setting at 290m ensures consistent airflow across most formations, which is the single most important factor accelerating drying.
Recommendations
3
- Prioritise south- and west-facing formations that have had maximum sun and wind exposure today; avoid north-facing or sheltered problems.
- Perform a touch test on the rock surface and check the ground at the base of formations — if the soil or peat is still damp, assume the rock retains internal moisture.
- If tomorrow's forecast trace rain (0.1mm) materialises, consider waiting until Aug 10–11 when a sustained dry spell with improving temperatures should ensure fully dry conditions across all aspects.
Marginal — Assess Conditions
72%
7 days ago
The most significant rainfall was 3.7mm on Aug 4th and 1.6mm on Aug 5th, followed by a dry day yesterday and only a trace (0.1mm) today. With strong westerly winds and moderate summer temperatures, exposed south and west faces are likely dry, but north-facing formations and sheltered hollows may still hold residual moisture from the recent rain cluster.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Brimham's scattered tower and pinnacle formations mean individual boulders dry at very different rates — south-facing exposed towers dry rapidly while north-facing recesses and undercuts between formations can stay damp for days.
- The open moorland setting provides excellent wind exposure from all directions, which is the single biggest drying advantage at this venue and compensates for the moderate-high altitude.
- Seepage can persist in horizontal breaks and along bedding planes on the larger formations (e.g., Cubic Block area, Lover's Leap) even when vertical faces appear dry.
- As a National Trust site, access is generally reliable but car park charges apply; check NT website for any seasonal path closures or event restrictions.
Warnings
2
- Do not assume the rock is dry throughout — surface gritstone can appear dry while internal moisture still weakens grain bonds, especially on north-facing aspects.
- Today's trace precipitation (0.1mm) may add surface moisture; if mist or drizzle is encountered on the moor, wait for it to clear and allow additional drying time.
Reasoning
The rock received a cumulative ~6mm over Aug 3–5, with only one full dry day (Aug 6) and a trace today; while not heavy rainfall, internal moisture may persist in porous gritstone despite surface drying.
Strong westerly winds (23–27 km/h) since Aug 5 and moderate temperatures (~16°C) have provided reasonable drying conditions for approximately 36–48 hours, which is borderline adequate for light-to-moderate rain on exposed faces but may be insufficient for sheltered aspects.
Structural risk is low-to-moderate; the total rainfall was modest and summer temperatures mean no freeze-thaw concern, but gritstone grain cohesion is still compromised if internal moisture remains.
Mid-summer conditions are generally favourable with adequate daylight and warmth, though the recent cooler spell (15–16°C) has slowed drying compared to typical summer conditions.
Contributing Factors
6
A total of ~5.8mm fell between Aug 3–5, with the heaviest single day being 3.7mm on Aug 4, providing enough moisture to penetrate the porous gritstone surface.
Consistent westerly winds of 23–27 km/h since Aug 5 have significantly aided evaporative drying across exposed faces.
Aug 6 was the only completely dry day since the rain, and today has a trace of 0.1mm, meaning the 48-hour drying benchmark has not been clearly met.
South and west faces benefit from prevailing wind and afternoon sun, but north-facing sides of individual towers will have dried much more slowly.
Temperatures of 16–17°C with humidity around 73–75% provide reasonable though not ideal evaporative conditions for summer.
The open, elevated setting at 290m ensures airflow around all formations with no tree shelter, which is a major drying advantage over valley-bottom crags.
Recommendations
3
- Focus on south- and west-facing exposed towers and pinnacles where wind drying has been most effective; visually check and touch-test rock before committing to any route.
- Avoid north-facing slabs, horizontal breaks, and low-level sections near the ground where moisture lingers longest — check for damp ground at the base of formations as a proxy for internal moisture.
- Tomorrow (Aug 8) looks significantly better with warm temperatures forecast at 23.6°C, lower humidity (61%), and continued wind — consider waiting one more day if conditions look marginal today.
Marginal — Assess Conditions
72%
9 days ago
The last meaningful rain was 3.7mm on August 4th followed by 1.6mm on August 5th, giving only one full dry day so far with moderate winds and overcast conditions. The exposed position and strong westerly winds are helping, but with only ~30 hours of drying since the last rain and relatively high humidity, a visual check on arrival is essential — particularly on north-facing formations.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Brimham's scattered tower and pinnacle formations mean every face has a different aspect and micro-climate; south- and west-facing faces exposed to the prevailing wind will be significantly drier than sheltered north-facing recesses.
- The horizontal breaks and ledge systems on many formations collect and channel water, creating localised seepage lines that can persist well after the main faces have dried.
- The exposed moorland setting at 290m means the strong westerly winds (24–27 km/h recently) are a major drying asset, but also mean conditions can feel much colder than valley temperatures suggest.
- National Trust site with seasonal access considerations — check NT opening hours for the car park and respect any path closures on the moorland.
Warnings
2
- Do not climb on any face that feels cool to the touch or shows darkened patches — the gritstone may appear surface-dry while retaining damaging internal moisture.
- Rain is forecast for August 9–10 (up to 8.1mm on the 10th), so the drying window is limited; plan accordingly.
Reasoning
A total of 5.3mm fell across August 3–5, with the most significant event being 3.7mm on August 4th; with only one dry day since (today, August 6th), internal moisture is likely still present in more porous sections and sheltered faces.
Strong westerly winds (24–27 km/h) and the exposed hilltop position are accelerating surface drying significantly, but moderate temperatures (~17°C) and relatively high humidity (74% average today, dropping to 47% mid-afternoon) mean internal drying is incomplete after just ~30 hours.
The recent rain was light-to-moderate (5.3mm cumulative) rather than a heavy soaking, so deep saturation is unlikely, but surface and near-surface weakening of the gritstone is still plausible on faces that received direct rain.
Mid-summer conditions are generally favourable with warm temperatures and long days, but the recent cool, humid spell has reduced drying efficiency compared to the warm, dry period earlier in July.
Contributing Factors
6
A cumulative 5.3mm fell over August 3–5, with only one full dry day elapsed since the last precipitation.
Sustained westerly winds of 24–27 km/h on the exposed moorland are significantly accelerating surface evaporation.
Average humidity around 74% today (dropping to 47% mid-afternoon) is limiting the drying rate compared to ideal conditions.
South- and west-facing faces will be substantially drier than north-facing formations, meaning conditions vary enormously across the venue.
Daytime highs of 17°C today are modest but adequate for evaporation, especially combined with the wind exposure.
Heavy cloud cover through the morning limits solar drying, but clearing skies from mid-afternoon should help exposed faces dry further.
Recommendations
3
- Focus on south- and west-facing formations that have had maximum wind and sun exposure; avoid north-facing recesses and lower sections of formations where moisture lingers.
- Check the base of boulders and the ground around the crag — if the peat or soil is still damp, the rock likely retains internal moisture.
- The afternoon window (15:00–19:00) offers the best conditions today as humidity drops to ~47% and some sun breaks through; avoid early morning climbing when humidity is above 80%.
Do Not Climb
92%
11 days ago
Brimham Rocks received 9.3mm of rain today (including a heavy 5.5mm burst at 16:00 and further showers), with more rain forecast tomorrow (5.0mm). The rock is currently wet and will not have adequate drying time for safe climbing today or in the immediate days ahead.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Brimham's scattered tower and pinnacle formations mean many faces are sheltered from prevailing wind despite the exposed moorland setting, so sheltered north-facing sides of individual boulders can hold moisture significantly longer than south-facing aspects.
- The moorland plateau at 290m often sits in low cloud and mist during humid SW airflows, which can keep humidity near saturation and effectively halt drying even when it isn't raining.
- Seepage lines are common at the base of many formations where water drains through the gritstone and pools — base-level problems and lower slab routes are the last to dry.
- National Trust site with permissive climbing access; irresponsible climbing on wet rock risks both permanent route damage and potential access restrictions at this high-profile venue.
Warnings
2
- Climbing on wet gritstone causes permanent, irreversible damage to holds and route surfaces — please wait for the rock to dry.
- Today's rain was heavy enough to saturate the rock internally; surface-dry appearance in coming days does not mean the rock is safe to climb.
Reasoning
The rock is currently saturated from 9.3mm of rain today, with the heaviest burst (5.5mm) arriving mid-afternoon and further showers this evening — the gritstone will be thoroughly wet through.
With 5.0mm more rain forecast tomorrow and humidity at 89%, meaningful drying cannot begin until August 6th at the earliest, and even then trace precipitation (0.3mm) and moderate humidity will slow progress — a full 48-hour drying window from the last significant rain is unlikely before August 8th.
After absorbing rain totalling ~14mm across today and tomorrow, the gritstone will suffer substantial strength loss (potentially 30%+ compressive reduction), making hold breakage and surface damage a real concern.
Summer temperatures are adequate for drying when conditions allow, but the current unsettled spell with high humidity and repeated showers is preventing the warm dry weather needed to cure the rock.
Contributing Factors
7
9.3mm total precipitation today including a 5.5mm downpour at 16:00 has thoroughly soaked the gritstone.
5.0mm forecast for August 5th with 89% humidity means the rock will be re-wetted before any drying can occur.
Small amounts of precipitation (0.3mm each day) on August 6th and 7th will further delay the drying clock, preventing a clean 48-hour dry window.
Brimham's exposed moorland position and forecast winds of 28–32 km/h will help accelerate surface drying on wind-facing aspects once rain stops.
Humidity has averaged 72% over the past week and will peak at 89% tomorrow, significantly slowing evaporation from the porous gritstone.
Daytime temperatures of 17–19°C later in the week are reasonable for drying, though below the recent highs of 24–28°C.
1.8mm forecast on August 9th threatens to reset drying progress just as conditions might begin to improve.
Recommendations
3
- Do not climb today or tomorrow — the rock is actively wet and will remain so through at least August 6th.
- The earliest realistic window to assess conditions on-site is August 8th, but only if the trace rain on the 6th and 7th remains negligible and wind maintains good exposure.
- Check the ground at the base of formations before climbing — if the soil or peat is damp, the gritstone above is almost certainly still holding internal moisture.
Marginal — Assess Conditions
62%
12 days ago
The rock had a good drying window from July 28–August 2 after only light rain (2.0mm on July 26), and today's midday conditions are warm, dry, and breezy — but 2.1mm of rain is forecast for this evening, and further rain is expected tomorrow and through the coming week. A narrow climbing window exists this afternoon on south- and west-facing formations if the rock feels completely dry to the touch, but conditions will deteriorate from tonight onward.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Brimham's scattered tower and pinnacle formations mean every face has a different aspect — south-facing towers will be significantly drier than north-facing ones right now, so choose your formations carefully.
- The exposed moorland position and today's ~20 km/h easterly wind will have aided drying on west-facing surfaces, but sheltered gullies and recesses between formations can stay damp much longer.
- National Trust site with permissive access — busy summer weekends can see heavy foot traffic; respect any seasonal closures for nesting birds on specific formations.
- Some formations have seepage lines and mossy bases that retain moisture well beyond what the main faces show; always check the base of the rock before committing.
Warnings
2
- Rain is forecast from 20:00 tonight — do not start any long routes or projects late in the afternoon.
- The coming week looks repeatedly wet; do not assume a single dry day between showers is enough to dry gritstone properly.
Reasoning
The last meaningful rain was 2.0mm on July 26 (8 days ago), followed by only trace amounts (0.1mm) on July 27–28 and July 31, giving a substantial drying window through warm, breezy conditions — the rock interior should be well dried on exposed faces, though tonight's incoming rain will re-wet surfaces.
Seven days of mostly dry weather with temperatures around 17–22°C and moderate wind (17–26 km/h) on an exposed moorland site provide excellent drying conditions for the July 26 rain; south- and west-facing formations are very likely dry through to their interior.
Structural risk is currently low for well-dried faces given the extended dry spell, but will increase rapidly after tonight's and tomorrow's rain — climbing on any surface that feels even slightly cool or damp should be avoided.
Mid-summer conditions are generally favourable with long days and warm temperatures, though the incoming unsettled spell from tonight through the week will bring repeated wetting cycles that prevent proper drying.
Contributing Factors
6
The last significant rain (2.0mm) was on July 26, with only trace precipitation since, giving 7+ days of effective drying on exposed faces.
Humidity drops to 35–43% with temperatures reaching 24°C and ~21 km/h wind from 11:00–18:00, creating an excellent short drying and climbing window.
2.1mm of rain is forecast from 20:00 onward today, which will re-wet surfaces and begin a new wetting cycle.
Rain is forecast on 4 of the next 5 days (totalling ~9.8mm), meaning sustained drying will not occur until at least August 9.
Brimham's exposed position at 290m ensures good air movement across the rock, which has significantly accelerated drying over the past week.
South- and west-facing formations are likely fully dry from the extended dry spell, but north-facing and sheltered faces may retain some dampness in recesses.
Recommendations
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- If climbing today, stick to the afternoon window (11:00–19:00) on south- and west-facing formations and physically check each surface is warm and completely dry before climbing.
- Avoid north-facing formations and any areas with visible moss, seepage, or cool-to-the-touch rock even during this afternoon's dry window.
- Plan to be off the rock well before 20:00 when rain arrives, and do not plan to climb again until a sustained 48-hour dry spell follows the incoming unsettled period.
Climbing Outlook