Art,
Was stationed at Ft. Lewis, I know what you're talking about. The Seattle Rain Festival, Jan 1st - Dec 31st!!!

Flying in heat is something we just learn to deal with here in SW Oklahoma. June - August is 90+ with 100+ nothing out of the ordinary. I usually get out to the field around 7-7:30 the morning, and done flying by noon.
The plus side is that we never really shut down for the winter either. We get flying days throughout the winter, so I never have to put my planes away for the winter.
Ken