Weather.com was my source for Philly and Memphis. Don't even think you can argue Philly is hotter than Memphis. Memphis is a designated staging area for Hell. Both for heat and tormenting!<g> Well, all I can say is this. Years ago I went to a Texas Rangers game in early August when it was in the 90's in the evening with high humidity. Saturday night in Philly it was around high-80's to 90 with horrible humidity. Both times I wore the lightest t-shirt I had, and both times they were totally drenched before the third inning. It was so hot both times that I only drank Coke and lemonade, I didn't dare touch beer in that kind of heat.
Last Saturday, during the day, was probably the nastiest day we've had all summer. It hit around 96 and the humidity was sky high.