Well at least in south MS it is. Today, my run wasn't bad and felt wonderful when I started. However, I got out to where the flight line is and the heat and humidity hit me hard. The head wind was nice, but when I reached my turn around point I got exhausted fast. I had some good tunes on, which is a big help, but it can only do so much. My GPS watch was left at home so I had to guess at time. :P. Ordered me a Halo II headband and my heart rate monitor. I have read that they help with training... a lot.