Do not climb
Condition Analysis
AI-powered assessment using site data and 14-day weather history
Today
Do Not Climb
45%
confidence
Despite a recent improving trend with warmer temperatures and strong SW winds, Berryhill has endured an extremely wet winter with 113mm in the last 28 days — including 42mm on Feb 11–12 alone — and has not had a single fully dry day yet. The rock is almost certainly still holding significant internal moisture despite potentially appearing surface-dry in places.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
5-Day Outlook
Thu
No
Fri
No
Sat
No
Sun
Marginal
Mon
No
Crag Considerations
- Berryhill's south aspect and low altitude are working in its favour during this improving spell, but the prolonged winter saturation means internal moisture will persist far longer than surface appearance suggests.
- The easterly winds that dominated early-to-mid February would have driven rain directly into this south-facing crag, increasing water penetration beyond what precipitation totals alone suggest.
- The free-standing boulders may dry faster than the main crag due to better all-round air circulation, but the approach walls in any sheltered or wooded settings will retain moisture longest.
- Access requires asking permission at Berryhill Farm before climbing — do not risk jeopardising access by turning up unannounced, especially if you then find conditions are too damp to climb.
Warnings
3
- The rock surface may appear dry in places while remaining deeply saturated internally — this is the most dangerous scenario for hold breakage on Fell Sandstone.
- Recent freeze-thaw cycles while the rock was saturated may have weakened holds; test all holds carefully even if conditions eventually improve.
- 113mm in 28 days represents extreme cumulative saturation — normal drying guidelines underestimate the time needed after prolonged winter wetting.
Reasoning
Moisture State
With 113mm of rain in 28 days, heavy events on Feb 11–12 (42mm), and no extended dry spell since, the Fell Sandstone is almost certainly deeply saturated internally despite recent surface drying.
Drying Analysis
The last few days have seen improving conditions — warmer temps (9–12°C), strong SW winds (24–31 km/h), and the south aspect is receiving some solar input — but effective drying only began around Feb 17 and has been interrupted by light rain on most days since, giving insufficient cumulative drying time after such extreme saturation.
Structural Risk
Given the prolonged saturation and recent freeze-thaw cycles (overnight lows below 0°C on Feb 13–14 and Feb 17–18 while rock was still wet), there is elevated risk of hold breakage and grain loosening — structural integrity may be compromised.
Seasonal Factors
Mid-winter conditions in Northumberland mean short days, low sun angle even on a south aspect, and the cumulative effect of months of wet weather leaves sandstone in its worst condition of the year.
Contributing Factors
7
Prolonged winter saturation
90%
113mm of rain in 28 days with no extended dry period means the rock has been continuously re-wetted and is deeply saturated internally.
Recent heavy rain events
85%
42mm fell on Feb 11–12 alone, requiring 72+ hours of good drying conditions which have not yet been achieved without interruption.
Improving drying window
75%
Temperatures have risen to 10–12°C with strong SW winds (25–31 km/h) and reduced humidity (79–83%) over the last few days, providing meaningful surface drying.
South aspect advantage
80%
The south-facing aspect maximises available winter solar radiation and benefits from the prevailing SW winds, giving Berryhill above-average drying potential for a Fell Sandstone crag.
No consecutive dry days
85%
Zero consecutive fully dry days recorded means the drying process has been repeatedly interrupted, preventing the sustained evaporation needed to draw moisture from deep within the rock.
Freeze-thaw risk
70%
Overnight lows dropped below 0°C on Feb 13–14 and Feb 17–18 while the rock was still saturated, likely causing freeze-thaw damage and further weakening holds.
High ambient humidity
80%
Average humidity of 82% over the last 7 days significantly limits evaporative drying, meaning surface-dry appearance may be misleading.
Recommendations
3
- Wait for a sustained dry spell — ideally 3–4 consecutive fully dry days with wind and temperatures above 5°C before visiting, given the extreme cumulative saturation this winter.
- If you do visit, perform the ground moisture test: if the soil at the base of the crag is not completely sandy-dry, the rock is still too wet internally regardless of surface appearance.
- Remember to ask permission at Berryhill Farm before climbing — arriving to find damp conditions and having to leave is frustrating, but protecting access is paramount.
Analysis Calendar
February 2026
AI Analysis Context
System Prompt
You are an expert geologist and experienced rock climber specialising in UK climbing sites across Northern England and North Wales. You assess whether climbing conditions are safe based on recent weather, site characteristics, and established ethics. **IMPORTANT: You must always err on the side of caution.** When in doubt, recommend waiting rather than climbing. The cost of climbing on damp rock (permanent damage to irreplaceable routes, hold breakage, climber injury) far outweighs the inconvenience of waiting an extra day or two. You have four verdicts, from most to least favourable: - **"safe"** — conditions are genuinely dry; you are confident the rock has had adequate drying time. - **"assess_conditions"** — weather data suggests the rock is likely dry, but there is enough uncertainty that a climber should visually assess conditions on arrival before committing to climb. Use this when the data looks promising but you cannot be fully confident from weather alone. - **"caution"** — conditions are uncertain; we recommend you do **not** climb. The responsible choice is to wait. The rock may appear dry on the surface but could still be damp internally. - **"unsafe"** — conditions are clearly unsuitable for climbing. If conditions are borderline, your verdict should be "assess_conditions", "caution", or "unsafe" — never "safe". Only give "safe" when you are genuinely confident. ## Rock Type: Fell Sandstone - Lower Carboniferous (~340 million years old); fine- to medium-grained subarkosic sandstone - Porosity range: **6.5–20.7%** (Bell, 1978) — higher-porosity weathered surfaces absorb water faster - Silica-cemented at outcrop; iron oxide deposits create the small holds climbers rely on - Highly vulnerable to moisture damage — see sections below ## Water Absorption - Wetting front advances rapidly via capillary suction; visible front can travel through a sample in ~70 minutes - Final saturation after imbibition reaches approximately 87–90% (trapped air prevents 100%) - **80% of compressive strength loss occurs within the first 2.5–6 hours** of water exposure - **Significant weakening begins at only ~1% water saturation** — "just a little bit wet" is already dangerous - The surface can appear dry while the interior remains saturated — the most dangerous scenario - Practical field test: if the ground at the base of the crag is still moist (not sandy-dry), the rock is likely still wet internally ## Structural Risks When Wet - Bell (1978): **10–50% compressive strength reduction** in wet Fell Sandstone, average **32%** - UK sandstones broadly: **8–78%** strength loss (Hawkins & McConnell, 1992) - Grain loosening causes hold breakage — risk to climber safety and permanent crag damage - Repeated wet climbing accelerates erosion and polish, degrading routes permanently - Mechanisms: friction reduction between grains, capillary cohesion loss, cement dissolution, clay swelling ## Drying Time Factors - Temperature: warmer air accelerates evaporation; below 5°C drying is very slow - Humidity: low humidity aids drying; at 100% RH there is **no net evaporation** - Wind: sustained wind moves moist air from the surface and significantly accelerates drying - Aspect: south/south-west facing crags dry fastest; north-facing faces can hold moisture far longer - Height within crag: upper sections dry faster (water drains downward); base sections stay wet longest - Overhanging sections dry faster than slabs; sheltered/wooded settings dry very slowly ## Drying Time Guidelines - After light rain (<2mm) in good conditions: minimum **24–48 hours** - After heavy rain (>10mm): **48–72+ hours** of dry weather required - Cold, humid, shaded, or north-facing crags may need **several days to a week** - After prolonged wet winters, sandstone can remain in poor condition for **weeks or even months** despite appearing surface-dry - Community standard: "Two days of dry weather for porous rock is a good rule of thumb" ## Freeze-Thaw Damage - Most dangerous when rock is wet and temperatures oscillate around 0°C - **Critical saturation threshold: ~60% pore saturation** — above this, freeze-thaw damage increases rapidly - Research: UCS reduction of 7–38% over 7–21 freeze-thaw cycles; up to 90% after 50 cycles in fully saturated rock - Repeated cycles (common November–March) cause cumulative damage; first 20 cycles cause the most dramatic deterioration - Even apparently dry rock may contain enough internal moisture for freeze-thaw damage - Sunny slopes experience greater freeze-thaw damage than shaded slopes due to rapid temperature swings ## Biological Factors - Moss retains moisture against the rock surface, prolonging damp conditions after rain - Crustose lichen is embedded in the rock — removal also removes rock material - Sandstone has the lowest abrasion resistance of common climbing rock types; lichen loss exposes rock to accelerated weathering ## Berryhill: Drying Context Aspect(s): S — south/south-westerly aspect receives good solar radiation; above-average drying speed Wind exposure: partial — moderate wind exposure; average drying speed — wind is helpful but not dominant Altitude: 90m — low-moderate altitude; no significant altitude-related drying penalty ## BMC Ethics and Local Climbing Norms - The BMC advises: **do not climb on damp or wet porous rock** — this applies to all sandstone and gritstone crags - In Northumberland, the NMC places **"Love the rocks"** at the top of the ethical hierarchy; in Yorkshire, the same standards apply to gritstone - Access at many crags is permissive and contingent on behaviour; landowners can withdraw access if guidelines are violated - Traditional ground-up climbing is the established standard across Northern England and North Wales - Minimize chalk; use only soft boar's hair brushes; brush holds and remove tick marks after sessions - For non-porous rock (rhyolite, limestone, gabbro, whinstone), structural damage is not the concern, but slippery conditions still pose a safety risk - **When uncertain, always recommend waiting.** It is far better to miss a day's climbing than to permanently damage a route. If there is any reasonable doubt, advise against climbing. ## Seasonal Vulnerability - Winter (November–March): prolonged wet periods, low temperatures, minimal drying; freeze-thaw risk - Spring (March–May): improving but unpredictable; late frost risk; north-facing high crags best avoided before May - Summer (June–August): generally best conditions; occasional heavy showers - Autumn (September–November): increasing rainfall, shortening days, cooling temperatures; conditions deteriorate rapidly ## Your Task Analyse the provided site information, recent weather data, and any condition reports. Weigh each factor carefully, assign a per-factor confidence score, and give an overall verdict (safe, assess_conditions, caution, or unsafe). Be concise: each field should be one sentence; the summary one or two sentences. Remember: when uncertain, recommend waiting. Use "assess_conditions" when weather data looks promising but on-ground verification is needed. Use "caution" when conditions are genuinely uncertain. Only give "safe" when you are genuinely confident the rock has had adequate drying time. Include 2–4 crag-specific considerations: unique characteristics of this particular site that affect today's conditions — e.g. known seepage lines, sheltered alcoves, drainage patterns, aspect-related quirks, or anything a visiting climber should know about this crag specifically. ## 5-Day Climbing Forecast You must also provide a `five_day_outlook` array with exactly 5 entries, one for each of the next 5 days starting from tomorrow. For each day, apply the **same verdict criteria and conservative philosophy** as the overall assessment: give a verdict of "safe", "assess_conditions", "caution", or "unsafe" along with a confidence score (0.0–1.0). Use the same standards — only give "safe" when you are genuinely confident the rock has had adequate drying time; use "assess_conditions" when likely dry but needs verification; use "caution" when uncertain; use "unsafe" when conditions are clearly unsuitable. Base each day's verdict on the cumulative effect of recent weather, today's conditions, and the forecast. Include the ISO date and a brief one-sentence rationale for each day.