Plus, heating and cooling experts weigh in on the financial and environmental impacts of choosing too high or low a setting.
beautiful entryway with smart thermostat
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You can officially settle arguments over your home's thermostat settings—during the hottest and coldest months of the year—for good. We asked two heating and cooling professionals to name the exact temperature your thermostat should read during the summer and winter, keeping in mind comfort, environmental impact, and energy efficiency.

The Best Summer Temperature

When the heat of summer kicks in and your home's air conditioning kicks on, you likely make a mad dash to the thermostat to keep comfortable. According to Michael Lopes, the Operations Manager at Reliance Home Comfort, make sure you're not tweaking that dial too much on your hunt for cooler air—and, ultimately, you don't have to. The perfect summer temperature for your home is roughly 70 degrees Fahrenheit. "This is a comfortable temperature for most people, but many things can influence how that feels," he says—after all, a humid 70 degrees feels a lot different than a dry 70 degrees.

Adjust as Needed

That being said, as outdoor conditions change—and with warmer summers and record-breaking heatwaves, they are bound to change—you may find yourself adjusting your thermostat to keep you and your family comfortable, which taxes your HVAC unit. "As the outdoor temperature increases, your air conditioner needs to work a bit harder to keep up with the temperature displayed on the thermostat," says Traci Fournier, the VP of Operations of One Hour Heating and Air Conditioning. "One of the main jobs of your AC unit is to remove excess moisture from the air, so when there is added humidity, it can be more difficult for the unit to run as efficiently."

In short, while 70 may be perfect in drier climes, as soon as that dew-point starts to track upwards, you may need to adjust your thermostat to compensate.

The Best Winter Temperature 

On the flip side of the dial is winter, which requires us to bump on our heating units. Fournier, however, advises customers to keep their thermostats set on the lower side. "During the winter months, I'd suggest keeping your heating system set at around 68 to 70 degrees," she says. "This may seem a bit low, but it is ideal to avoid overworking the system to heat the house. If you raise the temperature too much, your unit will struggle to stay at this higher temperature while competing with the cold weather outside, causing unnecessary strain on your HVAC."

Drop to 65 Degrees at Night

Bump the heat too high, and Fournier says you may also find yourself dealing with another uncomfortable winter problem: higher heating bills. "At night, people want to turn their furnace to extremely warm temperatures, which can be a big mistake," she says. "Keep your unit set around 65 degrees or so. If you're a bit cold, bundle up—it's much more cost and energy efficient to sleep with multiple blankets than to lead your unit to over-exhaustion!"

To fight the freeze, Fournier suggests cozying up with your comfiest, warmest pajamas. "Also, consider adding blackout curtains to keep your space warmer during the nighttime," she says. "Pull the shades back during the daytime to let the complimentary warmth of the sunshine in."

Eco-Friendly Home Temperatures

According to Lopes, what feels good to you isn't necessarily best for the environment (or your energy bill). "Environmentally-friendly temperatures are a few degrees different than what feels comfortable," he says. "Smart thermostats might show you an 'eco' or 'leaf' icon when you are set to an environmentally-friendly temperature. This reduces energy usage, but you might need to wear a sweater in cold months or keep a fan handy in the summer."

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!).

Comments (2)

Martha Stewart Member
September 15, 2022
I follow the guidelines the furnace-a/c installer recommended for maximum energy efficiency, give or take a couple degrees as needed, and assuming everyone is wearing seasonal clothing! Winter-set thermostat at 68 daytime, 70 evening (sitting, watching TV), and 65 at bedtime. Summer-set thermostat at 74-76. When away during the day set at 78-80. Setting it higher than that means your a/c unit will work twice as hard lowering the temperature after you get home. I agree 70 is too low in the summer, especially if the vent is overhead and pointing toward you! We installed a deflector to direct the air away from us. It hits the opposite wall and disperses around the room without hitting us directly. Circulating the air with a fan works well if the thermostat is set a little higher.
Martha Stewart Member
September 15, 2022
Were any of the "Heating and Cooling Experts" women? If not, your investigation is a failure. Women feel temperature much more acutely than men since their nerve endings are closer to the top of their skin than men. Men have a layer of protection on their skin and that is why temperature changes don't affect them like it does women. 70 degrees is much too cold for a home interior. Remember, people are wearing summer clothing indoors, too. In the winter, it would be fine since people are wearing winter clothing indoors.