4)Your groceries get cooked on the way to the car from the store.
3)Homeless guys ask if you can spare some Freon.
2)Too hot to wear undies
1) The squirrels are dipping their nuts in my ice tea.
Bonus signs:
Gangsta's can't wear hoodies
Jerry lawler is selling fireworks on tv
Jerry's snow cone : (not lawler) lines long
all you hear is the hummmmm of air conditioners