Also: Open your windows at night (assuming it's cool enough) and shut them as soon after sunrise as you can. Usually the temperature starts rising at sunrise, n

Also: Open your windows at night (assuming it's cool enough) and shut them as soon after sunrise as you can. Usually the temperature starts rising at sunrise, not surprisingly. See this graph, for example: https://forecast.weather.gov/MapClick.php?lat=40.751&lon=-73.9981&unit=0&lg=english&FcstType=graphical https://forecast.weather.gov/MapClick.php?lat=40.751&lon=-73... IME, temperature increases much more quickly outside than inside, and your home will stay cool. Add fans - much more energy efficient than AC - as needed. When I need AC, it's usually not until around 4pm or 5pm, even on hotter days. I cut my energy bills by ~70% using this and other measures.