Can I climb today
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Each area's page says yes, no or maybe for today and the week ahead, hour by hour, from the national weather model and how fast that rock dries.
How long rock takes to dry after rain
After a proper soaking, 2 mm of rain or more, these are the waits the site works with. A light shower needs less, and wind, sun and dry air shorten all of them.
| Rock | Exposed, sunny boulders | Most of the area | Shaded spots |
|---|---|---|---|
| Sandstone | about 18 hours | about 30 hours | about 42 hours |
| Gritstone | about 14 hours | about 24 hours | about 34 hours |
| Conglomerate | about 11 hours | about 18 hours | about 25 hours |
| Limestone | about 8 hours | about 14 hours | about 19 hours |
| Granite and gneiss | about 7 hours | about 12 hours | about 17 hours |
| Basalt | about 8 hours | about 14 hours | about 19 hours |
These are the model's estimates, tuned on Fontainebleau sandstone. Local rules come first: in Saxon Switzerland and the Czech sandstone areas you don't climb for 24 to 48 hours after rain.
Signs the rock is still wet
- Darker patches on the rock, especially low down and on the shaded side.
- Holds that feel cold, greasy or slightly soft, or sand that comes off on your fingers.
- Damp streaks below cracks, breaks and pockets. On granite and limestone that's seepage, and it can last for days after heavy rain.
- Chalk that turns to paste instead of drying white.
- Wet sand or moss at the bottom of the boulder, which you'd carry onto the holds on your shoes.
Why it matters on sandstone
Wet sandstone is weaker. Holds snap and wear away faster, and a broken hold is gone for everyone. That's why Fontainebleau, Saxon Switzerland and the Czech sandstone areas all ask climbers to wait. If you're not sure, touch the holds you'll use most. If any feel cool or damp, leave it for another day.
Humidity, dew and wind
Above about 92% humidity, rock barely dries at all, even without rain. A clear, still night can leave dew on the holds until the sun reaches them. Wind does more than sun: a steady breeze can dry an exposed boulder in a few hours, while a sheltered one in the trees stays damp all day.
Questions
Is it too wet to climb today?
It depends on where. If it rained in the last day or two, sandstone is probably still too wet, and granite or limestone may be dry on top but seeping. Each area page on this site gives a yes, no or maybe for today, hour by hour, from the weather forecast and how fast that rock dries.
How long after rain can you climb on sandstone?
After a proper soaking, about 18 hours for exposed, windy boulders and up to 42 hours for shaded ones, by this site's model. In Saxon Switzerland and the Czech sandstone areas the local rule is to wait 24 to 48 hours.
Can you climb on wet granite?
It won't break like sandstone, but wet granite is slick, so you'll slip off holds and pads get muddy. The surface dries within hours in wind and sun. Cracks and breaks can seep for days after heavy rain.
Is it OK to climb on wet limestone?
Limestone doesn't soak up water, so it dries fast on the surface, but pockets, tufas and cracks seep long after rain, and polished limestone is very slippery when damp.
How can I tell if the rock is dry?
Look for darker patches and damp streaks below cracks, and touch the holds you'll use most. If they feel cool, greasy or sandy, or your chalk turns to paste, leave it for another day.