Down here in TX, we often have summer temps above 100 degrees. While we do have A/C (a MUST for here), we also have good insulation. That insulation makes all the difference! Another help is to have several layers, over the windows (mini-blinds, drape liners, drapes - the more layers, the cooler those windows will be). Also check around windows and door, for weather stripping deterioration.
If you don't already have ceiling fans, GET SOME!
