The ideal temperature to set your thermostat in the summer is 78 degrees Fahrenheit (26°C) when you are at home, according to the U.S. Department of Energy. This temperature is the sweet spot between staying cool and keeping your energy bill low. If you find 78 degrees too warm, you can make small adjustments by moving the temperature one to two degrees higher than normal to see if you are still comfortable. Each degree set above 72 can save you up to 3% on your cooling costs. When you are away, you can increase the temperature to 85 degrees Fahrenheit (29°C) or turn off the air conditioner entirely to save energy. If you have pets, keep indoor temperatures below 85 degrees Fahrenheit (29°C) . Programmable thermostats can help make monitoring your home’s temperature while you’re away easy.