When temperatures in Shreveport climb past 100 degrees, your air conditioner is working as hard as it possibly can. Sometimes that still is not enough to get the house as cool as you want. So what is the best temperature to set your AC at in summer? And how much can your system actually cool your home when it is truly blazing outside?
These are questions we hear constantly from northwest Louisiana homeowners, and the answers can save you money, protect your system, and help you set realistic expectations during our most brutal summer days.
What Is the Best Temperature to Set Your AC in Summer?
The U.S. Department of Energy recommends setting your thermostat to 78 degrees Fahrenheit when you are home and need cooling. That is the sweet spot between staying comfortable and keeping your electric bill under control.
Every degree you lower below 78 degrees adds roughly 3 percent to your cooling costs. That means setting your thermostat at 72 degrees costs about 18 percent more to run than setting it at 78 degrees, for the same amount of time. In Shreveport where air conditioning runs hard for seven or eight months, that difference adds up to real money.
Here is a simple temperature guide to work from:
| Setting | When to Use It |
| 78°F | When you are home and active |
| 82°F to 85°F | When you are away from home |
| 75°F to 76°F | When sleeping (most people sleep better slightly cooler) |
| Never below 68°F | Setting your AC this low can freeze the evaporator coil and damage your system |
These are starting points. Your comfort level matters, and every household is different. But staying as close to 78 degrees as you can while you are home is one of the most effective ways to manage your electric bill without suffering through the heat.
The 20-Degree Rule: Your AC’s Actual Cooling Limit
Here is something a lot of homeowners do not know, and it is important for setting realistic expectations during Shreveport summers.
Most residential air conditioners are designed to cool your home to about 20 degrees below the outdoor temperature. That is the standard limit for how hard a system can work.
What that means in real numbers:
| Outdoor Temperature | Realistic Indoor Temperature |
| 85°F | 65°F to 70°F |
| 90°F | 70°F to 75°F |
| 95°F | 75°F to 80°F |
| 100°F | 80°F to 85°F |
| 105°F | 85°F to 90°F |
Shreveport regularly hits 95 to 105 degrees from late June through early September. On those days, your system is not broken if it cannot cool your home to 72 degrees. It is simply hitting its physical limit. The heat coming through your walls, roof, and windows is coming in faster than your AC can push it out.
This is normal. It is thermodynamics, not a malfunction.
That said, if your home is consistently much warmer than the outdoor temperature minus 20 degrees, something else might be going on. We will cover that below.
What Happens on Extreme Heat Days in Shreveport
When outside temperatures push above 95 to 100 degrees, your AC will likely run almost continuously. That is not a sign that something is wrong. It is the system doing exactly what it is supposed to do under extraordinary conditions.
On these days, keep these things in mind:
Your home will probably be warmer than you want it to be. If it is 103 degrees outside, expecting your home to stay at 72 degrees is asking more than the system can deliver. Setting your thermostat to 78 degrees gives the system a target it can actually hit.
Running continuously is okay for short periods. Your AC is built to handle extended run times. What wears the system down faster is constantly cycling on and off, which is what an oversized system does. A properly sized system running long and steady is healthier for the equipment than one that short-cycles.
Humidity makes everything worse. On a 95-degree day with 85 percent outdoor humidity, the heat index can easily reach 110 degrees or higher. Your body relies on sweat evaporation to cool itself, and in highly humid air, that process slows down dramatically. Lower humidity indoors makes the same temperature feel significantly cooler. This is why humidity control matters as much as temperature.
Smart Temperature Strategies That Save Money
A few simple habits can dramatically reduce how hard your AC has to work and how much you spend each month.
Raise the Temperature When You Leave
When nobody is home, raise the thermostat by 7 to 10 degrees. There is no point in cooling an empty house to 78 degrees. Raising to 85 or 88 degrees while you are away can cut your cooling costs significantly.
Do not turn the AC off completely, though. Coming home to a house that is 100 degrees indoors means your system has to work extremely hard to pull it back down, which costs more than maintaining a higher setpoint all day.
Lower It at Night
Most people sleep more comfortably at slightly cooler temperatures. The outside air also cools down after midnight, which means your system does not have to work as hard. Setting your thermostat a couple degrees lower at bedtime is reasonable and your system can usually maintain it.
Use a Smart Thermostat
A smart thermostat is one of the most effective upgrades for a Shreveport home. It learns your schedule, adjusts temperatures automatically, and can be controlled from your phone. You can raise the temperature while you are at work and have the house cooled back down before you arrive home, all without thinking about it.
Many smart thermostats also display indoor humidity levels, which is valuable information for a Louisiana homeowner. Seeing both temperature and humidity in one place helps you understand why your home feels the way it does.
Close Blinds and Curtains During Peak Heat
Direct sunlight through windows adds significant heat to your home. Closing blinds or curtains on south and west-facing windows during the hottest part of the afternoon (roughly 2 p.m. to 6 p.m.) can noticeably reduce the load on your AC without touching the thermostat.
Why Humidity Makes Your Home Feel Hotter Than It Is
This matters more in Shreveport than almost anywhere else in the country.
When the air is very humid, your body cannot cool itself efficiently through sweating. The moisture in the air slows evaporation, which means your natural cooling system does not work as well. A home at 78 degrees and 65 percent humidity feels much hotter and stickier than a home at 78 degrees and 45 percent humidity.
Keeping indoor humidity between 45 and 55 percent makes the same thermostat setting feel several degrees cooler. This is why a well-maintained AC system that properly controls humidity can make your home feel comfortable at a higher temperature than one that only cools the air without managing moisture.
If your home feels uncomfortably sticky even when the AC is running, that is a separate problem from temperature, and it is worth addressing on its own. Our indoor air quality team can help you find the right solution for your home’s humidity challenge.
Reasons Your AC Is Struggling More Than It Should
If your home is consistently warmer than the 20-degree rule suggests it should be, your system may have a problem beyond just extreme outdoor heat. Here are the most common culprits.
Wrong System Size
An AC that is too small will run constantly and never reach your target temperature on hot days. An AC that is too big will short-cycle, meaning it turns on, cools quickly, then shuts off before removing enough humidity. Both cause comfort problems.
The right size is determined by a Manual J Load Calculation, not by guessing based on square footage or matching your old unit. If your system has always struggled to keep up even on moderately hot days, sizing may be the root cause.
Dirty Air Filter
A clogged air filter restricts airflow through your system. When airflow is restricted, the evaporator coil cannot absorb heat effectively and the entire system works harder to move less air. Check your filter monthly and change it every 30 to 90 days depending on your household.
Dirty Evaporator or Condenser Coil
The outdoor condenser coil releases heat from inside your home to the outside air. If it is caked with dirt, leaves, or debris, it cannot release heat efficiently. The same goes for the indoor evaporator coil. Dirty coils reduce your system’s cooling capacity significantly.
Low Refrigerant
Refrigerant is the substance that actually carries heat from inside your home to outside. If your system is low on refrigerant due to a leak, it cannot transfer heat the way it should. Signs include the system running a long time without cooling much, ice forming on the indoor coil, or hissing sounds near the outdoor unit.
Duct Problems
If your ducts are leaking, too small, or poorly insulated, cooled air gets lost before it reaches the rooms where you need it. Some rooms may feel much warmer than others. Duct cleaning and inspection can identify these issues and significantly improve how well your system performs.
Age and Efficiency
An older system simply cannot cool as effectively as a modern one. Systems from 10 to 15 years ago typically have SEER ratings of 8 to 12. Modern systems start at 13.4 SEER2 and high-efficiency models reach 20 SEER2 or higher. An older system working at full capacity may deliver less cooling per dollar spent than a properly maintained new system at a lower setting.
Things You Can Do to Help Your AC on Hot Days
When the heat index is above 100 and your system is working flat out, these steps help reduce the load:
- Run ceiling fans. Fans do not cool the air, but they make you feel cooler by moving air across your skin. This lets you tolerate a slightly higher thermostat setting comfortably. Ask us about our ceiling fan installation options.
- Avoid heat-generating activities during peak hours. Cooking on the stove, running the dishwasher, and using the dryer all add heat to your home. Shift these to mornings or evenings when possible.
- Seal air leaks. Gaps around doors, windows, and pipes let outdoor heat in and cooled air out. Weatherstripping and caulk are inexpensive fixes that make a real difference.
- Check your attic insulation. Most of the heat that enters a Louisiana home in summer comes through the roof. Poor attic insulation allows that heat to radiate down into your living spaces all day long.
- Keep the outdoor unit clear. Make sure plants, furniture, and debris are not blocking airflow around the outdoor condenser. It needs clear space on all sides to release heat effectively.
When Your Struggling AC Needs Attention
There is a difference between an AC that is working hard because it is 103 degrees outside and a system that is genuinely underperforming. Watch for these signs that something needs to be looked at:
- The system runs all day and cannot get within 20 degrees of the outdoor temperature even on moderate days
- Some rooms are much warmer than others with no obvious reason
- Your electric bills are significantly higher than last summer with no change in habits
- You hear unusual sounds like banging, squealing, or hissing from the indoor or outdoor unit
- Ice is forming on the indoor coil or refrigerant lines
- Airflow from vents feels weak
If any of these sound familiar, a professional AC repair call is the right next step. Catching a problem early is almost always less expensive than waiting until a breakdown forces an emergency call on the hottest day of the year.
If you need help right now and your system has stopped cooling, our 24/7 AC emergency service is available when you need it most.
