
Why is it that the same route on the same cliff can feel like velcro one day, and butter the next? Some climbers seem to treat it as though there is a "conditions roulette", maybe it will be good, perhaps not, who knows? The most successful climbers know that there is a science to predicting how sticky a climb will feel, and that it is not a random chance. And they also know how to implement this knowledge to their advantage.
Reading the forecast
There is so much more to know than just "will it be raining?" These days we have the benefit of access to detailed meteorological information, with breakdowns of important data like dew point, humidity, precipitation, wind speed and direction for any hour of the day, in advance. So what does it all mean?
Firstly, know your crag. What orientation is the cliff? Will the surrounding landscape have any impact on the wind? Is it affected by sea spray, or mountian fog? Secondly, apply the stats to your requirements. If you are pushing yourself to achieve a personal challenge, rather than just wanting a nice day out, these statistics make all the difference between success and failure.
Wind
Why is wind important? Wind dries damp holds, and also damp hands. Imagine the weather you need for hanging out your washing on the line, and then picture the same drying conditions on the crag. It matters particularly on 'continuous' climbs where chalking up between holds is difficult. A decent wind will dry your greasy mitts as you go along. Look out for faster wind speeds and check the direction. A good detailed forecast will show you how the wind is going to change throughout the day (which it usually does, being a capricious entity).
Dew point
Dew point indicates the atmospheric temperature below which water droplets begin to condense and form. This is massively important for climbers because the rock temperature changes less quickly than the actual temperature, meaning that a cold night with a quick rise in air temps throughout the day can lead to the rock condensating as it struggles to catch up. The bigger the difference between the dew point and the actual temperature, the less likely it is for atmospheric humidity to condense on the rock, ergo it feels drier and there is more friction. Typically sea cliffs are optimum with at least 7 degrees difference, inland crags are not as prone to harbouring the grease but you still ideally want at least 5 or 6 degrees between the two. If you get more than 10 degrees difference, it is going to feel like cheating!
Humidity
Measured in percentage, the UK often has higher humidity than other popular rock climbing destinations. We just get used to putting up with it. But we still get the odd magic day where it drops to around the 50% mark. The lower the humidity, the less you will sweat as you exert yourself, and the quicker the rock will dry off.
Cloud cover
Sun can be your friend as it can warm the rock and burn off grease. Or it can be your worst enemy..... We've all heard of 'redpoint clouds', which are notoriously hard to predict and often suck you in to setting off on a serious attempt, only to disappear just when you most need them. Don't be fooled by 100% cloud cover predictions - sometimes this can refer to a very thin layer of high cloud, which barely interferes with the scorching sunshine. Look out for low cloud predictions too as these can often materialise as fog.

Let's pretend you are stuck into a project or have a route goal in mind. You have two days to choose from. Day 1 looks more humid, with a lower wind speed and the dew point is very close to the actual temperature. Day 2 has better stats. Do you exercise patience and wait until day 2? Obviously, if your number 1 desire is to succeed on a climb, it makes sense to stack up the cards in your favour.
What if your time is limited though? If you don't have the luxury of being flexible to choose the better conditions, here are a couple of suggestions:
- Have more than one project on the go at any given time, at crags with different orientations / requirements. This might worry some that they are not focusing 100% on the task in hand, but it really does work. If you have a project at an East-facing crag, and another at one that faces South-West, you have more chance of capitalising on different wind directions and levels of cloud cover. It also does you no harm to mix it up a little. Thrashing the same piece of rock, session afer session, can be dispiriting and tire your body in damaging ways. Variety will give you some spice!
- Study the detailed breakdown of the forecast. If you must be at a certain crag on a certain day, with no alternative option, at least check exactly what time will be optimum for sending. Forecasts can tell you at what time of day the wind will be strongest and the humidity lowest. Don't waste this knowledge! If 2pm is the magic sending time, make sure you are warmed up and ready for a good burn then. This takes thought, planning and preparation, but it can save you that sinking feeling that you wasted all the good connies on your warm-up. Conversely, if 6pm looks best, don't beast yourself beforehand, save some beans for an attempt at the optimum time.
Indoor climbing
Conditions are also important indoors. Training in hot, sweaty environments can damage your skin and your ego. Admittedly, much of the environmental factors in climbing walls are out of your control. However, there are some ways you can improve things in your favour. Ask the manager if you can open doors / windows to create some air movement and ventilation (don't forget you are a paying customer and have some say in the matter!). If there are fans available, don't be afraid to point them in your direction if you need it. Take your time between goes when bouldering and cool your skin by standing in front of a fan whilst you are resting. Brush the holds! It might take some effort, but it's worth it on so many levels.
Remember that persevering with rubbish conditions can be detrimental to your climbing - shooting off damp holds is a leading cause of finger injuries. Also, you only have limited time, make the most of it by giving yourself the best chances. OK, admittedly if we always waited for the magical conditions before climbing in this country, we might never get out of our armchairs. The goal is not to spend all your time over-analysing. Rather, just bear in mind that we can know what is coming and we have some degree of control over it. Happy cranking folks!
Photo: Malham Cove, taken by Nadir Khan
Useful websites:
www.yr.no
www.wunderground.com
www.raintoday.co.uk