What Temperature Should You Set Your AC in a Florida Summer?
Around 78 degrees is the common recommendation for Florida summers when you are home, with higher settings when you are away.
Around 78 degrees is the common recommendation for Florida summers when you are home, with higher settings when you are away. In South Florida, humidity matters as much as temperature, so a well-maintained, correctly sized system that removes moisture will feel comfortable at a higher setting.
Recommended Settings
- Home and awake: 78 F, the Energy Star balance point between comfort and savings
- Away (4+ hours): raise it 7 to 10 degrees, but in Florida cap it around 80 to 82 F because of mold
- Sleeping: around 82 F works for many people, lower if humidity is under control
Each degree above 72 saves roughly 3 percent on cooling costs, according to the Department of Energy. A 7 to 10 degree setback for 8 hours a day can save up to 10 percent a year.
Why Humidity Changes the Answer
78 degrees at 45 percent humidity feels fine. 78 degrees at 70 percent humidity feels miserable. Your AC dehumidifies as it cools, which is why a healthy, correctly sized system matters more than the number on the thermostat. An oversized system short-cycles: it blasts cold air, satisfies the thermostat, and shuts off before removing enough moisture. If your home feels clammy at normal settings, the system may be oversized or low on refrigerant, not set wrong. That is a repair call, not a thermostat problem.
Away Settings That Will Not Invite Mold
Do not turn the AC completely off when you leave a Florida home, even for a weekend. Without the AC running, indoor humidity climbs fast, and mold can start growing within 24 to 48 hours once humidity passes 60 percent. Florida Power and Light recommends 82 degrees or warmer when away, with the fan on AUTO (not ON, which re-evaporates moisture off the coil). For a week-long vacation, 80 to 82 degrees is the safe compromise between the electric bill and a mold remediation bill.
Do Ceiling Fans Help?
Yes. The Department of Energy says a ceiling fan’s wind-chill effect lets you raise the thermostat about 4 degrees with no loss of comfort. Run them counterclockwise in summer, and turn them off in empty rooms. Fans cool people, not rooms.
When the Bill Is High No Matter What
If your bill stays high at 78, the thermostat is not the problem. Common culprits: a dirty condenser coil, low refrigerant, leaky ducts, or a system nearing end of life. A tune-up catches most of these. If the system is 12+ years old and struggling, read our guide on how long ACs last in Florida.
Frequently Asked Questions
Is it cheaper to leave the AC on all day in Florida?
The “it works harder to cool back down” idea is a myth. A higher indoor temperature slows heat flow into the house, so the system uses less energy overall while you are gone. Use a setback, not full off.
What temperature should I leave my AC on vacation?
80 to 82 degrees with the fan on AUTO. This keeps humidity in check and prevents mold while you are away.
Why is my house humid even with the AC on?
Usually an oversized system short-cycling, low refrigerant, or a dirty coil. All three reduce dehumidification. If humidity stays above 55 to 60 percent indoors, have it checked.
Do ceiling fans let me raise the thermostat?
Yes, about 4 degrees per the Department of Energy, with no reduction in comfort. They are the cheapest cooling upgrade in your home.
Need Help With Your AC?
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Cooling On Demand Inc. is a Florida Certified Air Conditioning Contractor, license #CAC1822848. Services: Tune-ups. Read our customer reviews.