The Effects of the Weather when walking and hiking
Mountains accentuate changes in weather conditions and local situations can accentuate these conditions.
Temperature falls markedly the higher you climb. Experts estimate that the temperature can drop by 1 degree Centigrade for every 150m rise in altitude.
In very dry air, the fall may be 1 degree Centigrade for 100m rise in altitude.
In cloudy conditions, this may be 1 degree Centigrade per 200m.
Air is usually drier and warmer on the lee side of a hill.
The precise relationship between wind speed and altitude is hard to establish. However, there is a funneling effect of wind at valley heads - often very noticeable in the Lake District.
It's estimated that an increase in actual wind speed can produce a significantly greater force on an object. If wind speed increases by factor of 3 (say from 10mph to 30mph) then force exerted will increase by factor of 9!!!
In mountain areas, rain is both more frequent and heavier - local conditions and topography can have a profound effect.
Rain or sleet in a valley may mean a blizzard at the top of hills.