I spent a glorious day on the ranges yesterday. Usually the team are groaning about the usual drizzly Bisley. Yesterday they were moaning about sizzly Bisley and wanted to pack in early. No pleasing some people. :-)
Shorts on since March/April and probably stay on 'til October ish.
I can't remember the last time I had my jeans on - shorts all the time, even when it rains. Just remember, your bare legs will dry out quicker than your jeans if/when it rains. As long as it's not cold, I'm fine with shorts on :)