Wind Chill and Lapse Rate Walking from my house situated at 300m a.s.l. in the Peak District today I was struck by how cold and damp it was. O.K. it’s January in the U.K. but it felt really cold. Suitably dressed for a cold day navigating on Kinder Scout There are two common factors that have an effect on the temperature whilst walking in British Hills. Wind Chill and the Lapse Rate. Why do we do it? 1. Lapse Rate A lot has been written scientifically and in depth about Lapse Rate. There is a good paper from Bangor University. However it is essentially the amount that air temperature decreases as you gain altitude. Although there are variables such as whether the air is dry or saturated, generally the temperature decreases around 6.5 degrees C per 1000m climbed. So for example if you were in Snowdonia, let’s say in Bangor at Sea Level and you were walking to Snowdon via Llanberis. Bangor 0m a.s.l.