Do you get any cooler temperatures there other times of the year?

Here in Detroit I do a 25 mile round trip pretty much daily and I don't shower when I get in. I'll skip the ride for heat when the morning dewpoint is over 68F or the temperature is over 75F or both. Otherwise I find I can control the sweat.

Another trick is to take it easy in the morning and ride a nice 16-18 mph clip. Takes me ~50 minutes to get to work. Then I ride home as fast as I can, usually 40 minutes and sweating like crazy.