Miami weather and climate guide

7-day forecast for Miami

Tonight in Miami, FL brings partly cloudy. Across the 8-day outlook, highs average 91°F and lows average 82°F, ranging from 81°F to 92°F. No day in the period shows a meaningful chance of precipitation.

Current conditions

Observed at Miami, Miami International Airport (KMIA) at 8:30 PM EDT.

Two seasons, not four

The dry season runs from November through April. Humidity drops to something comfortable, highs sit in the upper 70s to low 80s, rainfall is sparse, and the occasional cold front pushes through with a few genuinely cool nights. This is why the tourist season is winter here, the reverse of most of the country.

The wet season runs May through October. Highs climb into the low 90s, overnight lows barely drop below 78, dew points sit near 75, and it rains nearly every day. The change is not gradual — the wet season typically arrives within a week or two in mid-May as the subtropical ridge shifts north and moisture floods in.

The temperature range across the whole year is remarkably narrow. The difference between the average January high and the average August high is about 15 degrees, where Chicago's is more than 50. Miami's all-time record high is 100 °F, set once, and the record low is 27 °F, set in 1917. Water surrounds the city on three sides and the Gulf Stream runs just offshore, and water resists temperature change.

The afternoon thunderstorm clock

Summer thunderstorms in South Florida are not weather events so much as a daily schedule. The mechanism is the sea breeze, and the geography makes it unusually reliable: the Atlantic is on one side of the peninsula and the Gulf on the other, both feeding air inland as the land heats through the morning.

Those two sea breeze fronts move toward each other and collide somewhere over the interior in early afternoon. Where they meet, air is forced upward through a deeply moist, unstable atmosphere, and thunderstorms erupt — usually between 2 and 6 p.m., often producing an inch of rain in half an hour, then dissipating by evening as the heating that drove them fades.

This makes South Florida the lightning capital of the United States. Florida records more lightning deaths than any other state, and the reason is not just storm frequency but timing: the storms arrive precisely when people are at the beach, on a boat, or on a golf course. The 30-30 rule is the useful one — if thunder follows lightning by less than 30 seconds, the storm is within striking range, and wait 30 minutes after the last thunder before going back out.

Where the storms fire depends on the wind. An easterly flow pushes the collision line inland toward the Everglades, giving the coast a sunny afternoon. A westerly flow pushes it toward the coast, and Miami Beach gets the downpour. This is why a rainy forecast so often produces a perfect beach day, and why five miles matters here.

Hurricane season, and what actually matters

The Atlantic hurricane season officially runs June 1 through November 30, but the risk is heavily concentrated. Activity climbs through August, peaks around September 10, and falls off through October. Roughly three quarters of major hurricane activity happens between mid-August and mid-October.

Miami-Dade has the highest hurricane exposure of any US county, and the building code reflects hard experience. Hurricane Andrew in August 1992 came ashore just south of the city as a Category 5 with 165 mph sustained winds, destroyed more than 63,000 homes and caused about 27 billion dollars in damage. The investigation that followed found widespread construction failures, and the resulting code — impact-rated windows, reinforced roof connections, and a design wind speed among the highest in the country — is now the strictest in the United States. A house built to current Miami-Dade standards is a genuinely different proposition from one built in 1985.

Two things matter more than the category. First, surge: the metro area is flat and low, much of it under ten feet, and surge is what kills people. Know your evacuation zone, which is based on inundation modeling for your specific location, not on how strong the storm is. Second, timing: hurricane preparations take days, not hours, and the wind arrives well before the eye. Once tropical storm force winds reach the coast, it is too late to put up shutters or fill a gas tank.

King tides and sunny day flooding

Miami has a flooding problem that requires no storm at all. During the highest astronomical tides of the year — king tides, usually in September and October when the sun and moon align most favorably — seawater comes up through the storm drains and floods streets in Miami Beach and low-lying parts of the mainland on clear, calm days.

The geology makes it difficult to engineer away. South Florida sits on porous limestone, which means seawater moves through the ground rather than being held back by it. A seawall does not help much when water can come up from below, which is why the region has invested in pumps and in physically raising roads instead.

Sea level in the region has risen roughly eight to twelve inches over the past century, and the rate has accelerated. The practical effect is that tidal flooding events that used to happen a couple of times a year now happen considerably more often. If you are looking at property, the elevation of the specific lot matters more here than in almost any other American city.

The dry season and the rare cold snap

Winter is why people move here. From December through March, highs in the upper 70s, low humidity and abundant sunshine make it arguably the most pleasant urban climate in the country during the months when most of the US is miserable.

Cold fronts do reach the city, weakened by their long journey down the peninsula. A strong one can drop overnight lows into the 40s, which locals treat as a serious event and visitors from Minnesota find comic. Genuine freezes are rare enough to be historical: the hard freezes of 1977, 1989 and 2010 damaged crops across South Florida and remain reference points.

The dry season has its own hazard. With months of little rain, the Everglades and surrounding brush dry out, and spring brings brush fire season. Smoke from fires in the interior regularly drifts over the metro area in March and April, and it is the main air quality concern of the year.

Weather hazards to know about

• Hurricanes and storm surge

  June through November, sharply peaking in September

  The highest hurricane exposure of any US metro area. Surge, not wind, is the main threat to life — know your evacuation zone before the season starts and leave when told to.

• Lightning

  May through October, most afternoons

  South Florida leads the nation in lightning deaths. Storms fire almost daily in the wet season, usually mid-afternoon, exactly when people are outdoors and on the water.

• Flash flooding

  May through October

  Flat terrain, a high water table and porous limestone leave nowhere for water to go. Three to six inches in a few hours floods streets and stalls cars.

• King tide flooding

  September through November, on the highest tides

  Saltwater rises through storm drains onto streets with no rain involved. Corrosive to vehicles, and worst when a high tide coincides with onshore wind.

• Extreme humid heat

  June through September

  Air temperatures rarely exceed 95 °F, but dew points near 80 push the heat index past 105. Overnight lows near 80 give the body no chance to recover.

What to wear and pack, by season

Dry season (November to April)

Light clothing with one sweater or light jacket for evenings and for a passing cold front. This is the season that needs the least planning.

Wet season (May to October)

The lightest, fastest-drying clothes you own, plus a compact rain jacket rather than an umbrella — afternoon storms come with wind. Expect to change clothes midday.

Year-round essentials

Strong sunscreen and sunglasses. The sun angle at 25 degrees latitude is intense in every month, and the UV index reaches 8 or higher even in winter.

If you live here

A hurricane kit assembled before June: a week of water and non-perishable food, medications, batteries, a NOAA weather radio, cash, and digital copies of insurance documents stored somewhere off-site.