When a Dallas forecast calls for another 100-degree afternoon, lowering the thermostat to 68 can feel like the obvious answer. Usually, it is not. The best thermostat settings summer homeowners can use balance comfort, humidity control, energy use, and the actual capability of their air conditioning system. A thermostat setting that is too aggressive can leave a system running constantly without making the house feel meaningfully cooler.

For most North Texas homes, 78 degrees is a practical starting point when people are home and awake. From there, the right number depends on your home, household, insulation, sun exposure, and how well your AC is performing.

The Best Thermostat Settings for Summer Comfort

A commonly recommended summer setting is 78 degrees when the home is occupied. It is warm enough to reduce unnecessary demand on the air conditioner, yet cool enough for many households when the system is removing humidity properly. In Dallas, where long stretches of extreme heat are normal, this setting also gives an AC system a more realistic target than trying to hold the house in the low 70s all afternoon.

That said, 78 is not a rule that fits every family. A home with strong afternoon sun through west-facing windows may feel warmer at 78 than a shaded home at the same setting. Upstairs bedrooms often run hotter than first-floor living areas. Older adults, infants, and people with certain health concerns may also need a lower setting for safe, comfortable conditions.

The useful question is not simply, “What temperature saves the most money?” It is, “What setting keeps the home comfortable without forcing the equipment to run harder than necessary?” For many households, that range falls between 75 and 78 degrees.

When You Are Away

Raise the temperature modestly while the house is empty, generally to 82 to 85 degrees for a normal workday. A small setback gives the system a break during peak hours without allowing the home, furniture, and interior surfaces to absorb excessive heat.

Setting the thermostat much higher can be counterproductive in a Texas summer. When you return, the AC may need to run for a long time to pull down both the temperature and indoor humidity. In a well-insulated home that will be vacant for several days, a setting in the mid-80s is often reasonable. If you are leaving pets at home, follow their comfort and safety needs instead.

Overnight Settings

Many people sleep better in a cooler room. A nighttime setting of 74 to 76 degrees is common, especially in upstairs bedrooms. Rather than cooling the entire house significantly, consider using ceiling fans, keeping bedroom doors positioned for good airflow, and confirming that supply and return vents are not blocked.

A fan does not lower the room temperature, but it helps people feel cooler by moving air across the skin. Turn fans off in empty rooms, since they do not benefit the home when no one is present.

Why Dallas Humidity Changes the Answer

Temperature is only part of summer comfort. Indoor humidity has a major effect on whether 76 or 78 degrees feels pleasant. When humidity is high, the air feels sticky, and your body has a harder time cooling itself through perspiration.

A properly operating central air conditioner removes moisture as it cools. If your home feels damp, clammy, or warmer than the thermostat reading suggests, lowering the thermostat may not solve the underlying problem. The issue could involve an oversized system that short-cycles, dirty equipment, restricted airflow, duct leakage, refrigerant concerns, or a thermostat that is not reading the space accurately.

For a typical home, indoor relative humidity around 40% to 60% is a reasonable target. It may rise somewhat during very humid weather, but consistently high indoor humidity deserves attention. A whole-home dehumidifier can be a worthwhile option in some homes, particularly where comfort concerns persist even when the AC is cooling.

Avoid Big Temperature Swings

It is tempting to lower the thermostat several degrees when the house feels hot. But your AC does not cool faster because the thermostat is set lower. It runs at its normal capacity until the indoor temperature reaches the selected setting.

For example, setting the thermostat at 68 when the house is 80 will not cool it faster than setting it at 75. It only tells the system to keep running longer, which can increase energy use and may make rooms uncomfortably cold once the system catches up.

Program gradual changes instead. If your household prefers 76 in the evening, have the thermostat begin adjusting shortly before people arrive home. A smart thermostat can learn these routines, but a basic programmable thermostat can handle scheduled setbacks as well.

Settings That Protect Your HVAC System

Summer demand is hard on every air conditioner in the Dallas area. Thoughtful thermostat use helps, but it cannot compensate for neglected equipment or a system that is not sized or maintained correctly.

Keep the thermostat on “cool” and set the fan to “auto” in most situations. The auto setting runs the blower only during a cooling cycle, which supports better moisture removal. Leaving the fan in the “on” position can circulate air continuously, but it may also move moisture back into the home after a cooling cycle ends. Continuous fan operation can be useful for specific airflow issues, but it is not always the best choice for humidity control.

Change or clean the air filter on schedule, especially during heavy summer use. A clogged filter restricts airflow, reduces comfort, and can contribute to frozen evaporator coils or unnecessary wear. Keep outdoor condenser units clear of leaves, grass clippings, and stored items so heat can escape properly.

If your system runs nearly nonstop on a hot day, that does not automatically mean it is failing. During severe heat, a properly sized unit may run for long periods to maintain the thermostat setting. The concern is when it cannot keep the home reasonably comfortable, blows warm air, cycles on and off repeatedly, leaks water, makes unusual noises, or causes an unexplained jump in utility costs.

Room-by-Room Comfort Matters

One thermostat cannot always correct uneven temperatures throughout a larger home. Hot upstairs rooms, bonus rooms, sunrooms, and additions are frequent trouble spots. Closing too many supply vents to force air elsewhere is not a reliable solution and can create airflow problems for the system.

Start with the basics: open supply vents, keep return grilles unobstructed, use blinds or shades during direct afternoon sun, and make sure doors are not limiting airflow. If one area remains consistently warmer, the answer may involve duct repair, added returns, insulation improvements, zoning, or a ductless mini-split for a difficult room.

For commercial spaces, thermostat placement matters just as much. A thermostat near a front door, kitchen equipment, direct sunlight, or a server room can cause the entire system to respond to a poor reading. Offices, retail spaces, and light commercial buildings often benefit from a professional review of zoning, controls, and occupancy schedules.

When the Thermostat Is Not the Real Problem

A thermostat is easy to blame because it is where you notice the problem. Sometimes it is the issue, especially if it is outdated, poorly located, or not calibrated. More often, inconsistent cooling points to the HVAC system, ducts, insulation, or airflow.

Call for service if the thermostat is set normally but the home remains humid, certain rooms are much hotter than others, the system cannot maintain temperature, or the outdoor unit is cycling abnormally. A qualified technician can check refrigerant performance, electrical components, drain operation, blower airflow, duct conditions, and thermostat accuracy before recommending repairs or replacement.

M.B. Kiser Heating and Air Conditioning has served Dallas-area homes and businesses since 1945, with technicians equipped to diagnose both everyday cooling problems and more complex system concerns. A seasonal maintenance visit before peak heat is often the best time to catch small issues before they become an after-hours breakdown.

The right summer setting should make your home feel consistently comfortable, not force you to keep adjusting the thermostat all day. Start near 78 degrees, make modest changes for your routine, and let the way your home feels guide the final setting. If comfort still does not match the number on the display, the most helpful next step is to have the system checked rather than asking it to work harder.