The Lake District is one of the rainiest areas in Britain, but June, July, and August hold the best hope of fine weather and are the time for all the major festivals. You will, however, be sharing the roads, hotels, trails, and lakes with thousands of other people. If you must travel at this time, turn up early at popular museums and attractions, and expect to work to find parking. April and May, as well as September and October, are alternatives. Later and earlier in the year there will be even more space and freedom, but many attractions close, and snow on high ground may preclude serious walking without heavy-duty equipment.