Scientific American: Get ready to retire the white wardrobes, cover the grill and shutter the lake house. Labor Day Weekend marks the psychological and meteorological end of summer. While you're enjoying one last cold one this weekend or snapping photos on the beach, take a look at how the summer's average temperatures stacked up for a number of cities across the U.S. Was it hotter than average? Colder? About in the middle? The answer is . . . yes, depending on where you live. However, even with rounds of record...