We are finishing the third straight week with daily highs in 90s and I've biked to work almost every day. I am definitely getting acclimated to the heat, but I don't enjoy it. My clothes are soaked in sweat after each commute, even in the morning, and my average speeds have dropped about 1 mph. One the plus side, I've got daylight on both commutes and haven't had to deal with any rain in quite a while.