I thought it was hot yesterday.

No wonder.  It was the summer solstice – already?  Seems like it.  And I had been thinking it wasn't until next week.  From timeanddate.com:

June Solstice in Gulfport, Mississippi, U.S.A. was on
Sunday, June 21, 2015 at 11:39 AM CDT

I was in the garden picking tomatoes at 11:39 CDT, and thinking that the sun was beating down pretty hard.  As a matter of fact, the sun was beating down pretty hard!