Yeah what Martin says,Cross fell is probably the most exposed route in the area, High cup nick (out and back)would be a better option, Or the Askham fell moor divock Bridleways,ullswater singletrack are good all year round.
Doing the cross fell route is probably best done may to july before the Bracken gets High and after a week or so dry weather,nipping up the great dun fell road to the radar station and then over little dun fell is a quick version of this route and then do the Bridleway to Blencarn. In good dry conditions its a corker, with few gates, high speeds lower down and some stunning views from the top,Theres a good pub,campsite, yoof hostel and cafe in Dufton village.enjoy.