I kept wondering whether bouldering in the rain, or climbing on wet rock at all, is actually ok, so I did some digging and asked around.
So can you boulder in the rain or climb when the rock is wet? Bouldering in the rain usually isn’t a good idea, because some rock types like sandstone are far more likely to break off when they’re wet, and a snapped hold ruins the route for everyone. When it comes to wet rock in general, both for protecting the rock face and for your own safety, the rule of thumb is to stay off it.
Plenty of climbers travel a long way to try a route and don’t want a surprise storm to shut them down. But blanket claims about rock types can be misleading, or just not apply to the boulder in front of you, so it pays to gather as much local info as you can.
What Rock Is OK To Boulder While Wet?
Like I said, the type of rock has a huge effect on whether it’s safe to boulder while it’s wet. Some climbers feel it’s unethical to climb any rock while it’s wet, so keep that in mind too. That said, bouldering is a lot less damaging to the rock face than rope climbing, so it’s still worth weighing the different rock types when you decide.
Sandstone:
Generally, sandstone is dangerous to climb when it’s wet, because water makes sandstone weaker. On top of that, you’re much more likely to break handholds and footholds when sandstone is wet, so avoid it as much as you can. Still, not all sandstone is the same. The best way to learn what applies to your area is to ask the locals.
- Fountain sandstone around Boulder IS generally safe to boulder while wet.
- Nutall sandstone at the New IS generally safe to boulder while wet.
- Navajo sandstone is NOT safe to boulder while wet.
- Wingate sandstone found in the desert southwest is NOT safe to boulder while wet.
Granite:
Granite is generally the safest to climb while wet. That’s mostly because it’s very strong, not very porous, and dries quickly. Even so, there’s always a risk of water damage in cracks you can’t see at different levels of the rock, so it’s important to check the rock face before you get on and keep checking while you boulder.
Some spots, like Leavenworth in Forestlands, have reported small breaks in the granite hours after climbing, though nobody knows for sure if the rain was the cause.
Limestone:
Limestone is generally strong and less likely to break than sandstone when it’s wet. The catch is that a lot of climbers report limestone gets more slippery when wet, so any polished handholds or footholds become harder to climb and more dangerous.
One thing you can do is check the holds before you start, and clean your shoes first so you’re not dragging extra dust or mud onto the rock and making a slick climb even slicker.
If you’re new to bouldering, I’d wait until it dries before getting on routes in an area you’ve never been to.
How Long Does Rock Take To Dry?
Generally, it takes about 24 hours after rainfall before the rock is completely dry. Of course, some rock dries in under an hour and some takes a few days. It also depends on the environment the rock sits in, so it’s location dependent too.
Here are a few of the most common things to factor in when you’re guessing how long the rock you care about will take to dry.
Rock Type
Naturally, if the rock is more porous, it’ll take longer to dry than something non-porous like granite. There are a few reasons, but the big one is that rain soaks deeper into a porous rock face, and the deeper it goes, the longer it takes to dry back out. Because of that, not all rock needs the same amount of time between rainfall and dry conditions.
- Sandstone: depending on where it is and what kind it is, sandstone can take up to a few days to dry. Some red sandstone can take up to three days to fully dry, while some sandstone common in the Fountain, CO area only takes a few hours.
- Granite: granite generally dries quickly. That’s likely because it isn’t very porous, so water doesn’t soak into the layer of rock as much.
- Limestone takes more time to dry than granite and generally less time than sandstone.
Heat
Generally, if it’s hot outside, the rock dries faster than if it’s cold. Heat changes how fast water evaporates, so it changes how long the rock takes to dry.
If it’s really cold, the water may not evaporate at all and can freeze on the rock instead. In a really hot area, the water can evaporate moments after it hits the rock face.
Think about heat at every stage the rock gets wet: before, during, and after. The warmer it is at each of those points, the faster the rock dries.
Humidity
No surprise here, the humidity in the area also changes how fast the rock dries. In some desert spots, humidity sits well below 10% before and after a rainstorm, while more humid areas can run well above 30% before and after.
If there’s more humidity, the rock takes longer to dry, because there’s already a lot of water in the air and it’s harder for the water on the rock to evaporate.
How To Tell If Bouldering In The Rain Is OK On Your Route
If you’re on a quick weekend trip, or you flew halfway across the world only to get unexpected rain every day, you might be thinking about bouldering anyway, despite the risks above.
In that case you might be tempted to walk out to the route and size up the risk yourself, just in case you could boulder without a problem.
Local Weather Warnings
Depending on where you want to boulder, there may be local weather warnings. In a lot of spots in Zion National Park, for example, there are flash flood warnings almost every time it rains in certain seasons. People die every year because they ignore those flash flood warnings.
Don’t ignore weather warnings. If there are local ones, try to find another place to boulder. You can often drive an hour in one direction and find completely different weather.
The Approach
On top of the climb itself, think about the safety of your approach. If you’re in a mudslide-prone area, the approach can be seriously dangerous, so skip it. To find out if an area gets frequent mudslides, you can usually just run a quick search for ‘mudslides in (location)’, and if a lot comes up, it’s probably a more mudslide-prone spot.
There are plenty of places where the approach is likely safe and already dry, so use your best judgment.
Rock Type
I know I keep banging this drum, but that’s because it’s one of the biggest things boulderers worry about when they’re deciding whether they can climb while it’s wet.
If the rock is more porous, it’ll likely be riskier to climb. Erosion adds to the mix, and some rock, like sandstone, is just weaker when it’s wet.
See above for how safe each rock type is.
Cracks
Cracks in a bouldering route are handy for a clean climb, but they’re also a sign of weakness in the rock face. Generally, the more cracks there are, or the wider they get, the weaker the rock is.
When rock is wet, erosion isn’t only working on the outside of the face, it’s working inside every crack and crevice too.
Check each crack to see if it’ll hold your weight, along with any movement you might put through it while bouldering. If there’s any movement in the crack, stop climbing. The risk isn’t worth it. Not only could you break the rock face and ruin the experience for other climbers, but that rock could break on you or pin you.
Slipperiness
Certain rock types, like sandstone and limestone, get more slippery when wet. That isn’t about how sturdy the rock is, it’s that you’re more likely to slip and hurt yourself.
Remember that every fall is a ground fall, and some are more dangerous than others no matter how fat or wide your crash pad is. A rough landing is a big reason some boulderers even think about whether to wear a helmet.
Early in my climbing, I was sport climbing outdoors and it started to snow out of nowhere. I kept climbing despite the cold and wet. Along with my frozen toes, the rock got really slippery. I took a hard fall and bruised my knee badly. I could hardly walk without constant pain for over a week, and it took weeks to fully heal. Not worth it. (Side note: I was young and dumb, and hopefully I’ve gotten a little smarter since.)
Hold Stability
If you get to the point of checking individual holds, feel whether each one seems stable before you commit to the route.
If you test a few holds and they feel fine and you decide to keep going, keep checking every hold you pull on.
If there’s any sign a hold might break, boulder somewhere else. Like I’ve said a bunch of times here, a piece of the rock face breaking doesn’t just ruin the route for other boulderers, it can also hurt you.
Climbers’ Ethical Arguments And Wet Rock Bouldering
Climbing on wet rock is a popular and often heated topic among climbers. Most of the ethical arguments are about trad and sport gear chewing up the rock face, but there’s also plenty of concern for the integrity of handholds and footholds on the route, which ties right back to bouldering.
Climbing Erosion Ruins Rocks
This is probably the most common argument from climbers who think you should stay off wet rock. The idea is that climbing erosion (erosion caused by climbing) is more damaging when the rock is wet than when it’s dry.
A common rebuttal is that climbing erosion will eventually wear the rock face down anyway, even if climbers only climb when it’s dry, so climbers shouldn’t feel too much pressure to stay off when it’s wet.
Some Areas Rain Daily
This one comes up a lot for climbers who live somewhere that rains often and feel they should get to climb despite it. The idea is that there wouldn’t be any climbing in those areas if everyone had to wait for the rock to dry, so there’s no point sitting out the rain.
There aren’t many common rebuttals to this one.
Related Questions:
Where is the best place to boulder after it rains?
Bouldering indoors at a local gym is the best place to boulder after it rains. You skip all the safety and rock-integrity worries, and you’re likely to meet boulderers in your area who could be great climbing partners once the rock dries. If you’re weighing it up, here’s a rundown of the pros and cons of indoor bouldering.
Of course, not everywhere has a local gym (one of my favorite places to boulder is in St. George, Utah, and they don’t have a climbing gym yet). In that case there isn’t really a best place to boulder after it rains, unless you’re willing to travel to a gym.
Rained out for the weekend? That’s a good time to sharpen the parts of your climbing that don’t need rock at all. If you want short, practical sessions in your inbox, I put together a free weekly newsletter with 15-minute climbing drills you can do just about anywhere: Level up your climbing with 15 minutes of training.
Frequently asked questions
Can you boulder in the rain?
Generally, no. Bouldering in the rain isn’t recommended, mostly because some rock types like sandstone get weaker when wet and are far more likely to break holds, which ruins the route for everyone. A lot of climbers also see it as an ethics issue, since climbing erosion does more damage to wet rock.
Is it ok to climb when the rock is wet?
The general rule of thumb is to stay off wet rock, both to protect the rock face and for your own safety. Granite holds up best because it’s strong and dries fast, sandstone is the worst since water weakens it, and limestone stays fairly strong but gets slippery when wet.
How long does rock take to dry after rain?
Generally about 24 hours, but it varies a lot. Some rock dries in under an hour, while some red sandstone can take up to three days. Rock type, heat, and humidity all change how long it takes, with porous rock like sandstone taking the longest.
What is the safest rock to climb when it’s wet?
Granite is generally the safest to climb while wet, because it’s very strong, not very porous, and dries quickly. Even so, water can still hide in cracks you can’t see, so check the rock face before you get on and keep checking as you climb.
Where should I boulder when it’s raining?
An indoor gym is the best option when it’s raining. You avoid the safety and rock-integrity problems of wet rock entirely, and it’s a good chance to meet local climbing partners for when the rock dries out.
More About Bouldering:
- What Is The Minimal Gear Needed For Bouldering?
- Can You Boulder Alone? The 8 Benefits Of Climbing Alone
- The Complete Guide For Bouldering Grades: What You Should Know
- Should You Wear A Helmet For Bouldering?
- Can You Boulder In The Rain Or When The Rock Is Wet?
- First Time At The Bouldering Gym: What You Should Know
- Pros And Cons Of Indoor Bouldering
- Indoor Bouldering: Do’s And Don’ts For Beginners
- Bouldering For Beginners: What You Need To Know
- A Guide For Climbers: Bouldering Drills 101
- Is Climbing and Bouldering Good For Cardio?
