This summer in South Texas we have been experiencing 37 C days. During the peak of summer, it can get to 40 C, or a bit higher. That lasts about 2 months. We consider 32 C a pleasant day to go outside.
Air conditioning can get expensive depending on how well insulated your home is. A well insulated home doesn't cost too much to cool. The trick is to set it to dehumidification. If the air is humid, you'll be miserable at any temperature. As a dehumidifier, an air conditioner runs at lower power, but still cools. A dedicated dehumidifier can't help as it vents the hot air back into the same room.
Strategically, you can install a window unit in only the spaces you want to cool rather than trying to cool the entire home.
Air conditioning introduces another concern, mold. If the air is not properly filtered, the dust and humidity are a perfect environment for mold.
We start opening doors and windows once temperatures reach about 26 C, which is around November.
