Climbing in the heat: how to get a good session when it is too hot

The grade did not change, the air did

There is a particular kind of July session where nothing works. Holds you were solid on in April now spit you off. Your fingers slide, your feet feel vague, and you start quietly wondering whether you have got worse. You have not. The rock is the same. The air around it is not.

Every climber loses something in the heat, and the honest response is not to grit your teeth through it. It is to change what you are doing. A hot week is not a write-off, it just needs a different plan.

It is the sweat, not the thermometer

The usual story is that warm rock is slippery rock. The more interesting version is that the biggest problem is you.

Friction Labs, reviewing the research on climbing performance, makes the point plainly: temperature seems to have minimal effects on skin friction and force production, while humidity has a larger indirect effect through increased heart rate, sweat response and general discomfort. In other words, the heat is not softening the rock. It is opening your pores, and wet skin does not stick.

That is a useful thing to know, because it changes what you actually do about it. Chasing a few degrees is less important than chasing dry air and dry hands. A muggy 22°C day will feel far worse than a dry 26°C one, and if you have ever had a brilliant session in genuinely hot but bone-dry conditions, that is why.

Chase the hours, not the day

Give up on the middle of the day. Between roughly eleven and four you are climbing at the worst time, in the worst light, on the warmest rock, with the most sweat.

Early morning is the quiet win. The rock has cooled overnight, the air is drier, and nobody else is there. Evening works too, though rock holds heat for hours after the sun leaves it, so a west-facing crag at seven in the evening can still feel like an oven. North-facing walls and anything in tree shade are the reliable picks. If a crag gets sun until noon, arrive at six and be finished by ten.

The same logic works indoors. Most walls are hottest and busiest from six to nine in the evening. An early session, or a weekday afternoon if you can manage it, is a different building entirely.

Go where it is cold

Summer is the season some places come into their own. High-altitude granite, deep forest boulders, shaded limestone gorges and anything with a river running through it. Magic Wood in the Averstal sits at 1,300 metres under pine trees with cold water through the middle, which is exactly why it is a July venue and not an April one.

Height helps more than most people expect. So does aspect, and so does water. If your local crag is a south-facing suntrap, the fix is not better technique, it is a different postcode.

Change what the session is for

This is the part that actually makes a difference over a summer. If conditions will not let you climb at your limit, stop trying to.

A hot session is a poor day for redpointing a project and a good day for almost everything else:

• Volume on easy ground. Mileage, movement, mileage. Nothing here needs perfect friction.
• Technique work. Silent feet, straight arms, precise placements. Bad friction is honest feedback; if your feet are sloppy, you will know immediately.
• Weaknesses. The slab you avoid, the style you are bad at, the arete you have never touched.
• Strength and antagonists. Pull-ups, core, shoulders, the work that never needed the rock to be sticky.
• Rest. Genuinely. A deliberate down week in the worst of the heat is not lost time, it is the down week you were going to need anyway.

Log the session honestly and the summer stops looking like a gap. Track what you did and by September you will see the volume and the technique work sitting underneath whatever you send in autumn.

Small things that help

Skin first. Sweat softens the outer layers, and soft skin wears through fast, so a hot day is when flappers happen. Dry your hands properly before you pull on rather than chalking over damp fingers, because chalk on wet skin is just paste. Liquid chalk under a normal chalk layer gives you a base that lasts. Brush every hold you are about to use, since old chalk and grease from the last twenty attempts are doing you no favours.

Then the boring things that are not boring at all. Drink more than you think, and take salt with it, not just sugar. Sit in the shade between goes rather than standing in the sun looking at the problem. Give yourself longer rests than usual, because your heart rate is already elevated before you leave the ground. Keep your shoes out of direct sun, as hot rubber goes soft and vague.

And take fewer, better goes. Six half-hearted attempts on greasy rock cost you skin and teach you nothing. Two properly rested tries with dry hands are worth more.

The season is not the enemy

Every climber has a summer where they feel like they are going backwards. Mostly they are not, they are just measuring themselves against conditions that have changed.

Shift the hours, find the shade, pick sessions that suit greasy skin, and let the project wait for autumn. The rock will be sticky again in October, and the person turning up to it will be fitter, more precise and better rested than the one who spent July losing to a heatwave.