In (probably) most of northern Europe, it is somewhat cold and wet outside. Despite this fact, I'm trying to get as much outdoor climbing done as I can.

A backup plan for somewhat cold weather (i.e. around/slightly above 0°C) would be to try aid climbing, but we're wondering if this is a safe idea. My question is, as the title says:

Is mobile protection (i.e. nuts, cams, hexes etc.) less safe if the rock is (slightly) wet? Does this change if the temperature is around the freezing point? (Bonus points for references from official sources, e.g. manufacturers or climbing associations.)

This is not about heavy rain with water pouring down the rocks, but more about rock that hasn't completely dried from rainfall a few days past (or at most a light drizzle while climbing) where there might remain some really wet spots on the inside of some cracks or flakes. The temperature would be mostly above 0°C, but where one can't see beforehand with 100% certainty that there aren't any frozen spots in some of the cracks.

  • 1
    If you just want to train consider just top roping face with a safe route to the top.
    – paparazzo
    Commented Dec 26, 2016 at 18:18
  • @Paparazzi Incidentally, that is exactly our plan so far :-) (Better safe than sorry...)
    – anderas
    Commented Dec 26, 2016 at 18:44
  • I would argue as it has forced you to think about it, it is probably safer even if it is more likely to fail. Safety of natural placements is not a given, yet they are reliable enough complacency creeps in.
    – user5330
    Commented Dec 27, 2016 at 0:16

3 Answers 3


Mountaineers doing technical alpine routes certainly use rock pro under wet or icy conditions. However, the kind of routes they're climbing are typically not the kind of high-angle stuff that you have in mind when you go out for a day of rock climbing. There are people who do things like mixed rock/ice climbing, but you really have to know what you're doing. I've never done any aid climbing, but aid climbing in the rain sounds to me like a really, really bad idea, because often the placements are extremely marginal.

I think there are really two separate issues you want to keep in mind when attempting to apply your trad technique under wet conditions.

One is that lubrication reduces friction, so for example a cam in a flaring crack might not hold if it's wet, even though it would have held under dry conditions. But of course not all gear placements depend on friction. If you place a big hex in a constriction, no friction is required. And even with an active placement that requires friction, the way active gear works is based on the principle that as you increase the tension on the rope, the gear presses against the rock harder and harder, giving more friction.

The other issue is rock quality. Even on well known trad routes, there is sometimes rock fall. A rock can hold over and over again under whatever strain is applied to it by climbers -- which could mean placing gear behind it, or simply using it as a hold -- but one day, it comes loose. For example, there could be a refrigerator-sized boulder sitting on huge, sloping ledge at the top of a single-pitch climb, which everyone has been using as a belay anchor. It's been holding non-leader falls for years just fine. But on a day when it's raining hard, that amount of force might finally cause it to slide off.

Erosion is a natural process that shows bursts of activity at irregular time intervals due to conditions. If you're in the mountains during or soon after a storm, you will often see new rockslides. This is why, for example, there are huge debris-control dams at the bottoms of the canyons in our mountains in Los Angeles. Entire towns have been wiped out by boulders and mud during once-in-a-century storms. In other words, there is no guarantee that something will stay stable just because it's been stable for x years in the past.

You're describing temperatures hovering around freezing. One of the natural processes that leads to erosion is the situation where water, ice, or snow gets into cracks between rocks and then undergoes freeze-thaw cycles, expanding and contracting with each cycle. People quarrying rocks have sometimes used this effect intentionally to break rocks apart, e.g., by drilling holes in the rock and letting rain fill them.

The Trad Climber's Bible by John Long and Peter Croft has a brief section on climbing in the rain. They basically describe it as a misfortune that befalls you because the weather forecast was wrong, and they suggest common-sense ways of dealing with the emergency: don't panic; close your chalk bag and stick it under your clothing; slow down and be deliberate about your movements; place more gear than you normally would; pull on gear if necessary; avoid moss and slime.

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    I would add that this is also rock-dependant - sandstone while wet is a really bad idea (but then again not all sandstones all created equal), while granite isn't quite as bad.
    – Francky_V
    Commented Dec 26, 2016 at 17:05
  • This is a great answer, even though it doesn't really go in the direction that I expected. Our case is more like "That solid basalt UIAA 5/6 crack over there is way too cold for our fingers, and maybe a bit wet, why not try to aid it?", not "It's raining but I can't wait for better weather, let's go outside and start aid climbing some unstable sandstone". But I have to admit that the question wasn't completely clear here. So for now, I'll upvote your answer and accept it in a few days if no better one comes along. I hope that is ok with you :-)
    – anderas
    Commented Dec 26, 2016 at 18:37
  • 1
    Also wet limestone is a nightmare for cams - completely unreliable. My first trad experience was on limestone in rain. After trying out cams with backup and consistently failing, we resorted to nuts - a well placed nut holds everything (no guarantees).
    – imsodin
    Commented Dec 26, 2016 at 22:08

The short answer to that is yes - but the real answer is it depends.

If you are climbing on sandstone, this could actually be very dangerous & unethical. The issue with sandstone is that it tends to be a fairly porous rock. After heavy rains, it is likely to have absorbed some quantity of water in those pores. This weakens the rock, compared to the very same rock with empty pores. Depending on conditions (ambient humidity levels and rock itself), it may take some time before it is safe to climb again. The issues about climbing on wet (porous) sandstone is that it is much more likely to break off if you fall on your pro (not necessarily a huge chunk falling down, but you only need the surface to chip out to take out your cam/nuts...) and also that you could break holds. That's bad for safety AND for climbing ethics.

Red rocks (near Las Vegas) recommend 24 hours after rain before climbing - I've heard people talking about 36 hours there to be safe too: Las Vegas Climbing Council

However, Red River Gorge (Kentucky) is also largely sandstone though of a much stronger type. I've been climbing often there while it rained, mostly in the roofy areas where the rocks tends to stay dry, although it will begin to seep in the cracks if it rains enough. I also climbed there in the spring - with all the snow melting, even if the surface of the rock is dry, the cracks are often seeping so it is safe to assume there's moisture in the rock. It's mostly sport climbing though, but the point about the rock being liable to break is just as valid. Bolted routes at Red Rocks are just as discouraged after rains as trad climbs.

If you do a long route, and get caught in the rain, you may then have to climb on wet rock anyways. Of course there's a difference between taking a risk because elements force you to and walking to the crag voluntarily to take that same risk (wet rock). But to show it is not an absolute no-go, depending on rocks.

The main thing is that wet rock will bite less into your placements than dry one, generally speaking. So each placement should be considered with more caution - raise your standards as to what you will consider a good one. Chokes will tend to be less affected than cams because the friction doesn't matter as much - but be aware that it is more likely it will move after you go so be extra careful for this (perhaps equalize more than you otherwise would have).

Regarding freezing, I am aware of nothing that would make much of a difference between say 20 Celsius wet rock a 2C rock. If you mean below freezing, then I would point out that mix climbing (rock & ice) do use both ice screws & rock protections for their ascents (though these guys are crazy, IMO). One of the issue that I see with this however is that it may be more difficult to determine is the rock is fractured (because it may not ring as hollow if ice fills the cracks).

Regarding manufacturer's inputs:

Metollius seems to think so:

Metollius about wet/icy rocks

My opinion on this however (regarding manufacturer's input) is that they are all likely to say it is riskier just because of liability. They are unlikely to provide useful guidelines as to how much riskier or when it is safe regardless. E.g. to me the fact that they describe it as riskier doesn't mean it's a no-go - all things being equal, trad climbing is riskier than top-rope....

  • +1 for the shout out to not breaking off holds on sandstone after a rainstorm. Every time we can get this message to one more person...
    – erfink
    Commented Mar 18, 2017 at 0:16

I’ve been wondering about this for years. And then every so often I have no option but to place gear, and even belay anchors, on wet rock.

I’m confident for nuts it doesn’t matter. For cams though, I used to be more skeptical, but with time I gained confidence. Two days ago I’ve build a hanging belay anchor with 2 cams in a wet crack, and I’m still here.

No one took a whip, and I don’t say trust anectodal evidence, just saying that sometimes you have to learn by yourself.

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