As in any hilly and remote area it is as well to be prepared for any weather when out walking.
You can get a general forecast for the North West of England from the
Met Office website.
There are two local weather stations, at
Kirkby Stephen Railway Station and at
Tufton Lodge on Stainmore. These weather stations give you the weather as it is now at those two locations. Both are considerably higher up than the town of Kirkby Stephen, so can give a useful indication of wind speeds and temperature 'on the hill'.