Usually the best way to cool off a house around here is to open all the doors and windows after the sun goes down to let in the cold night air, then close 'em up come sunup and pull down your shades, trapping the cool inside and the hot outside.

I figured that out shortly after moving to northern CA, where it actually does cool down significantly at night. It kept me cool through most of the day, and saved me from paying *bend over* amounts of money to PG&E.