What’s the best thermostat setting for summer? According to MarthaStewart.com, the “ideal” temp indoors is 70 degrees. But if you want to save money and not crash the grid, the ideal setting is 78 degrees. A recent report from Energy Star, which is affiliated with the US Environmental Protection Agency and the US Department of Energy, affirms this; the company recommends settings that go well beyond 70 degrees come summertime: According to the energy company, 78 degrees is the ideal eco-friendly thermostat setpoint—a number that creeps up to 82 degrees overnight (and 85 degrees if you’re not at home!). Each degree above 75 saves about 3% on your energy bill.