When you leave your Florida home for the season, set the thermostat to 78–80°F rather than turning the AC off — this keeps indoor humidity low enough to prevent mold, warped wood, and musty odors while you're gone for weeks or months. It feels wasteful to keep paying to cool an empty house, but in South Florida the AC isn't just managing temperature — it's the only thing actively pulling moisture out of the air. Shut it off for a summer up north and you'll likely come home to a very different problem than a warm house.
78–80°F is the range that keeps humidity in check without running up your FPL bill for no reason. Go much higher than 80°F and the system stops removing enough moisture from the air to keep pace with South Florida's outdoor humidity, which regularly sits above 70% for months at a time. Go lower than 78°F and you're paying to cool a house nobody's living in — there's no comfort benefit to a colder empty home, only cost. For more detail on how these numbers were chosen, see our full breakdown in the best AC temperature guide for Florida.
Never turn the AC off completely for an extended absence, even to save money. This is the single most common — and most expensive — mistake snowbirds make. Without any dehumidification running, indoor humidity in a closed-up Florida home can climb past 80% within days. That moisture gets into drywall, wood furniture, cabinetry, and fabric, and mold can start growing in less than 48 hours in the right conditions. By the time you return in the fall, you may be looking at a mold remediation bill that dwarfs several seasons of cooling costs.
A standalone dehumidifier is not a substitute for keeping the AC running, though some snowbirds try to split the difference by shutting off the AC and running a dehumidifier alone. A dehumidifier can help in a pinch, but it doesn't manage heat buildup, and most residential units aren't built to run unattended and unmonitored for months — if the reservoir fills or the unit fails, you get no warning until you're back. Keeping the central AC running at 78–80°F handles temperature and humidity together, with far less risk of an unattended failure going unnoticed.
A smart thermostat is worth installing before you head north, even if you've never used one before. It lets you check your home's temperature and humidity from your phone anywhere in the country, and most models send an alert if the temperature spikes unexpectedly — which is often the first sign of an AC failure while you're away. Catching a problem in week two instead of discovering it in week twelve is the difference between a simple repair and a house full of ruined belongings.
Ask whoever checks on your home — a neighbor, property manager, or family member — to glance at the thermostat, not just walk through the rooms. A house can look fine while the AC has quietly stopped running for days. If you have a smart thermostat, share access with whoever's checking in so they get the same alerts you do, and give them your HVAC company's number in case something needs attention while you're away.
If you're leaving before or during hurricane season, your pre-departure checklist needs to cover more than just the thermostat setting. Surge protection for the outdoor unit, a secure condensate drain, and confirming the system is in good working order before a storm season with nobody home to notice a problem all matter more when you won't be around to catch an issue early. See our hurricane season AC prep guide for Miami for the full pre-storm checklist.
Before you head north for the season, MGM A/C Appliances can inspect your system, confirm it's ready to run unattended for months, and set up a thermostat schedule that protects your home while you're away. We serve snowbirds and full-time residents throughout Miami-Dade and Broward, from Aventura to Homestead, with free estimates and 24/7 emergency service and no after-hours surcharge — so if something comes up while you're gone, we can respond even if you can't. Call (786) 352-0084 before you leave.