Extreme Heat risk in Florida

Why Florida looks like this

Your realtor hands you the keys in July. The thermostat is set to 78, the air handler hasn't shut off since you walked in, and the power bill in the junk drawer says $310.

Florida sits between two warm bodies of water, so the air over the state is almost always soaked with moisture. When the National Weather Service issues a heat advisory for Tampa, Fort Myers, or inland Polk County, it's usually not the air temperature that gets you. It's the heat index — what it feels like when you add humidity to 95°F air. In many Florida summers, the heat index stays above 105°F for days.

FEMA's National Risk Index puts Florida at 5 out of 5 for heat. That reflects how many days sit above dangerous thresholds, how many people live in urban heat islands like Miami, Orlando, and Jacksonville, and how many homes depend on central AC by August.

What heat actually does to a house

Heat doesn't knock a house down. It sits on it. Asphalt shingles age faster when the attic underneath hits 140°F. Attic insulation settles. Wood floors gap at the seams. An AC unit that's already twelve years old runs twenty hours a day and quits in August — right when every HVAC company in Broward or Hillsborough County has a two-week backlog.

Then there's the humidity side. A sealed Florida house with a dead AC can start growing mold in 48 to 72 hours. That's the damage that ends up in claims.

Where the risk concentrates

South Florida — Miami-Dade, Broward, Palm Beach, and Monroe County in the Keys — gets heat plus overnight lows in the low 80s. Your house never cools off. Inland counties like Orange, Osceola, Polk, and Highlands run hotter in the afternoon than the coast because there's no sea breeze. The Gulf Coast from Sarasota through Lee and Charlotte counties mixes heat with the highest humidity in the state. Older homes with original windows and mobile homes take the worst of it.

Insurance gaps people miss

Here's the part that catches people off guard: there is no “heat damage” line on a Florida homeowners policy. Heat is not a named peril. If your shingles curl or your AC compressor burns out from overwork, that's typically wear and tear, and wear and tear is excluded on a standard HO-3.

What is often covered: fire damage from an overheated outlet, water damage from a burst AC condensate line — mold that follows may hit a separate sublimit — and food spoilage after a power outage, usually up to $500 or so.

The bigger Florida-specific trap is the wind-versus-flood split after a hurricane. Wind damage usually falls to your homeowners policy. Flood is excluded and needs a separate NFIP or private flood policy. Heat waves often follow storms, when the power is out and the house is sealed tight.

Also read your hurricane deductible. In Florida it's often 2% of dwelling coverage — on a $400,000 home, that's $8,000 out of pocket before insurance pays anything. And check the mold exclusion.

A practical weekend plan

If you have one weekend and a few hundred dollars, I'd spend it on the attic and the AC, not on a generator. Insulation and a smart thermostat pay you back every month in Florida. A generator sits in the garage waiting for a storm.

• Saturday morning: Get in the attic. If your insulation is below R-30, adding blown-in insulation is one of the few upgrades that pays for itself here.
• Saturday afternoon: Have an HVAC tech check the refrigerant charge and clear the condensate drain. A $150 tune-up prevents the August replacement.
• Sunday: Set the thermostat to 78 when you're home, 82 when you're out. Close blinds on south- and west-facing windows.
• Any day: Sign up for alerts through the Florida Division of Emergency Management and find your county's cooling centers.

One more thing: check on an older neighbor with a medical condition. Heat deaths in Florida often happen indoors, alone, in a house with a broken AC.

Questions we get

Does Florida homeowners insurance cover heat damage?

Usually no, not directly. Heat isn't a named peril, and wear and tear, deterioration, and mechanical breakdown are excluded. You're covered only when a named peril — fire, a burst pipe, a windstorm — causes the damage. Read the exclusions page before you assume anything.

Is extreme heat worse in Miami or inland Florida?

Different problems. Coastal South Florida deals with warm overnight lows and humidity that never breaks. Inland counties like Polk, Highlands, and Osceola hit higher daytime temperatures because there's no sea breeze, but they usually cool off more at night. For a house, the coastal version is harder on your AC because it never gets a rest.

What should I do if my AC dies during a Florida heat wave?

Get out of the house during the hottest hours — a library, a mall, or a county cooling center. Don't try to ride it out with fans alone; fans stop helping once indoor air passes about 95°F. Open windows at night only if it's cooler outside than in, and run a dehumidifier. Mold can start in two to three days.

Official maps and agencies

• Florida Division of Emergency Management — heat advisories, cooling centers, county emergency contacts.
• National Weather Service Heat Safety — heat index charts and what a watch, advisory, and warning actually mean.
• Ready.gov – Extreme Heat — household prep steps.
• CDC – Extreme Heat — health guidance for older adults, kids, and outdoor workers.

If you're buying in Florida, pull the FEMA National Risk Index page for your county and ask your agent, in writing, which perils are excluded. Heat won't show up on the seller's disclosure — but the July power bill will show up every year.