Re: Temperatures can soar over 400C
When going for a run in the great outdoors anything over 5C and I'm in shorts. I will wear a jacket (breathable) for rain up to 10C but the chances of getting exposure above 10C (while generating lots of personal heat) are very much less.
I also grew up running in Auckland, NZ and therefore learned both a tolerance of being VERY wet while running and enjoying running in the rain (it temporarily helped with the humidity and was cooling).
So no coat above 10C, fine. If I'm running.