In reply to planetmarshall:
Reading Nan Shepherd's book The Living Mountain last night, about the Cairngorms and was struck by this sentence 'snow, that hardly ever fails to powder the plateau about the third week of September'.
That was written in 1944, and a quick check of snowfall records from the past 10 years shows that snow in September is now unusual, rather than expected. Long hot summers seem a long way off, but the path towards them has begun.
Highly recommend a read, it's a lovely book about the mountains and nature.