VARF has pushed their season a little earlier due to the heat now. It's running mostly in May and June now, but yes, those June days can get pretty brutal out there at times. I usually aim to armor up down there, and that's sometimes hard to do.
MDRF often has some brutal days in the early part of the season, and particularly the opening week as it's in August. We've been very lucky this year, with pleasant weather most weekends and the opportunity to wear armor almost the entire time. In fact, I've worn some amount of armor much more frequently than ever before, only wearing other garb on a couple of days.