What Temperature Should I Set My Thermostat to in Summer?
Picture this: it is the middle of July, the kids are home, the house feels sticky, and your energy bill from last month is still fresh in your memory. You walk over to the thermostat and just stare at it. Do you bump it down and deal with the bill later, or suffer through it? We get that question from homeowners all over Shelby County every single summer, and we want to give you a real, honest answer.
The short answer is that the right thermostat setting in summer depends on whether you are home, sleeping, or out for the day. There is no single magic number, but we can walk you through what actually works and why. When it comes to what temperature you should set your thermostat to in summer, the best starting point is a combination of comfort, humidity control, and a little strategy.
What the Data Actually Says
The U.S. Department of Energy recommends 78 degrees Fahrenheit when you are home during the summer. That number is not arbitrary. It is the sweet spot where most air conditioning systems run efficiently without overcooling a space. Every degree you drop below 78 can add 3 to 5 percent to your cooling costs, and in an Alabama summer that runs from May through September, those percentages stack up fast.
We know 78 might feel warm, especially if you have been keeping your house at 70 for years. But here is something worth trying: raise the temperature slowly, one degree at a time, over a few days. Most people find they adjust and barely notice the difference after a week. Pair that with ceiling fans running counterclockwise and it feels even cooler without the extra cost.
What to Set It to When Nobody Is Home
When the house is empty, there is no good reason to cool it like someone is sitting in the living room. The DOE recommends raising your setting to around 85 degrees while you are away during the day. That keeps the home from getting dangerously hot and stops the system from running full tilt to cool an empty space.
One thing we always tell our customers: do not let the house climb above 85 to 88 degrees for extended stretches. In Alabama’s humid climate, if the AC goes too quiet for too long, indoor humidity starts rising, and that creates the perfect conditions for mold. Our AC maintenance service includes a full check on how your system handles humidity, which matters just as much as temperature around here.
Sleeping Temperatures Are a Little Different
Sleep experts generally recommend keeping bedrooms between 65 and 68 degrees for the best rest. That is a fair bit cooler than what we suggest during the day, and there is good reason for it. Your body temperature naturally drops during sleep, and a cooler room supports that process.
The good news is you do not have to cool the whole house down to 66 every night. A programmable or smart thermostat lets you schedule cooler temps for bedtime and warmer temps for when you are out. That kind of scheduling is one of the easiest wins we see homeowners make on their energy bills. Set it once and let it work for you.
Humidity Changes Everything in Alabama
Here is something that does not get enough attention: humidity affects how temperature feels far more than most people realize. Shelby County and the wider Birmingham area regularly see relative humidity above 70 percent during the summer months. At that moisture level, 78 degrees can feel closer to 85. Your AC is not broken. Alabama is just genuinely that humid.
Your air conditioner does double duty in our climate. It cools the air AND pulls moisture out of it. If your system is aging or oversized, it might be cooling quickly but not running long enough to properly dehumidify. The result is a house that hits the target temperature but still feels muggy and uncomfortable. If that sounds like your home, we can take a look and find out what is really going on.
Quick Tips That Make Any Thermostat Setting Work Better
A few simple habits go a long way toward making your home feel cooler without touching the thermostat at all. These are things we see make a real difference for the families we serve.
- Keep ceiling fans spinning counterclockwise so they push cool air down into the room
- Close blinds and curtains on south and west-facing windows during the hottest afternoon hours
- Run your oven, dryer, and dishwasher in the evening instead of midday
- Check your air filter monthly and replace it every one to three months during heavy summer use
- Look into a smart thermostat if you do not already have one; the scheduling features alone pay for it over time
These are not complicated changes, but they all reduce the workload on your system and help you stay comfortable at a higher thermostat setting.
When the Thermostat Is Not the Problem
If your home is not reaching the temperature you set regardless of where you put the dial, something else is going on. Low refrigerant, duct leaks, an aging system, or the wrong equipment size for your home can all make your thermostat feel useless no matter what setting you choose.
We have been helping Shelby County homeowners troubleshoot exactly these kinds of issues since 2005. A professional tune-up is the fastest way to find out whether your system is performing the way it should. We would rather help you catch a small problem before it becomes a costly one.
Ready to Make Your Home More Comfortable This Summer?
If your home is struggling to stay cool or you are tired of guessing at thermostat settings, we are here to help. Our team knows what Alabama summers put your equipment through, and we are ready to help you get ahead of it.
Wondering if we are the right team for the job? We were voted Best HVAC Company in Shelby County two years in a row, and we take that trust seriously every time we show up.
Reach out to us here and we will schedule a visit that works for you.
Frequently Asked Questions
What temperature should I set my thermostat to in summer to save money?
The U.S. Department of Energy recommends 78 degrees when you are home. Raising it to 85 when you are away can save up to 10 percent annually on cooling costs. We work with a lot of homeowners in Shelby County who have made this shift and seen a real difference in their bills.
Is 72 degrees too cold for a thermostat setting in summer?
It is not unsafe, but it is expensive. Every degree below 78 increases your cooling costs by 3 to 5 percent. In an Alabama summer that runs five or six months, that adds up to a meaningful amount over the season.
Why does my home feel hot even when the thermostat shows a cool temperature?
High humidity is almost always the reason. Alabama summers push indoor humidity levels up, and if your AC is not effectively dehumidifying, the air will feel warmer than the thermostat reads. We see this a lot, especially in homes with older systems.
How often should I change my air filter in the summer?
Check it every month during heavy summer use and replace it every one to three months depending on the filter type. A clogged filter makes your whole system work harder and is one of the easiest problems to prevent.
Does a smart thermostat really save money in Alabama?
Yes, and we see it consistently with our customers. The scheduling features mean your system is not working hard to cool an empty house. In a hot, humid climate like ours, that kind of automation leads to real savings.