Well for me… Last year.
It was most certainly the weather.
Training – get the miles in. Get the legs strong, eat well drink plenty.
Go at your own pace esp downhill ( saw some nasty falls last year).
But most of all have the right clothing !! The amount of people in early or developed stages of hypothermia last year was quite unbelievable.
Especially relevant if you are from the south – Cold Fell is called that for a reason. A wild day in Surrey ain’t the same as a cold day in the lakes !