It's really hot in Tennessee.
I made this graph using data from the National Oceanic and Atmospheric Association (click here!) to reassure myself that and end was in sight. The summer temperatures don't look quite as high as I expected, but these are averages throughout the day. I couldn't find very extensive data on daily highs and lows.
Notice how much variation there is in January weather! January has a mean temperature of 33.09*F with a standard deviation of 13*. July 1st, on the other hand, has an average temperature of 71.52* and a standard deviation of 4.8*. Yes, quantile plots were normal.