The climate of the north and central parts of the U.S. state of Florida is humid subtropical. South Florida has a tropical climate.Köppen Classification Map, clearly showing South Florida has a true tropical climate (the image will take a few seconds to load) Over the past decade, Florida's average June temperature has risen to about , compared to just for the same month over the long-term period since 1895; additionally, June temperatures have risen by approximately 2 °F compared to 50 years ago. A 2024 peer-reviewed study found that locations in the Florida Peninsula and Keys have experienced increases of more than 1.5 extreme autumn heat-stress days per decade since the 1950s, with the largest trends observed in coastal urban areas. There is also a defined rainy season from May through October when air-mass thundershowers that build in the heat of the day drop heavy but brief summer rainfall.
In October, the dry season sets in across much of Florida (starting early in the month in northern Florida and near the end of the month in deep southern Florida) and lasts until late April most years. Fronts from mid-latitude storms north of Florida occasionally pass through northern and central parts of the state which bring light and brief winter rainfall. Mid and late winter can become severely dry in Florida. In some years the dry season becomes quite severe and water restrictions are imposed to conserve water. Predicting these changes is essential for farming, construction, and tourism.
FAWN, the Florida Automated Weather Network, provides accurate weather predictions. This system is useful for determining current weather and predicting how Florida's climate will change. While most areas of Florida do not experience any type of frozen precipitation, northern Florida can see fleeting snow or sleet a few times each decade.
The USDA Hardiness Zones for the state range from Zone 8B () in the extreme northwestern panhandle, to Zone 12A () in the lower Florida Keys.
The Gulf Stream running through the Florida Straits and then north along the eastern Florida coast keeps temperatures moderate a few miles inland from around Stuart on the east coast to Fort Myers on the west coast of the state year-round, with few extremes in temperature. The tropical ocean current also provides warm sea surface temperatures, giving Florida beaches the warmest ocean surf waters on the United States mainland. Florida's geography also makes it vulnerable to the effects of climate change, both in the intensification of extreme weather such as intensified hurricanes as well as coastal flooding and other effects of sea level rise.
Pressure
The low pressure measured from an extratropical cyclone was 28.84 inches/976.7 hPa during the Storm of the Century.National Weather Service Forecast Office Tallahassee, Florida. Tallahassee Weather Extremes. Retrieved on June 3, 2007. From a tropical cyclone, the lowest pressure measured was 26.35 inches/892 hPa in the Florida Keys during the Labor Day Hurricane of 1935.Eric. S. Blake, Edward N. Rappaport, and Christopher W. Landsea. The Deadliest, Costliest, and Most Intense United States Tropical Cyclones from 1851 to 2006 (and Other Frequently Requested Hurricane Facts). Retrieved on June 3, 2007. The highest known pressure measured statewide was 30.74 inches/1041.1 hPa in Tallahassee on February 5, 1996, and January 4, 1979.
Wind
Over the winter prevailing winds are out of the north across the panhandle south to near Orlando, but are variable in the rest of the state. The summer season sees generally east and southeast winds across the peninsula. During the summer months, the average wind pattern implies a surface ridge axis which normally lies across central Florida, with easterly winds from Tampa southward and southwest winds across northern Florida. The peak wind gust during the 1930 through 1997 period was at Miami International Airport during Hurricane Andrew.National Climatic Data Center. Climatic Wind Data for the United States. Retrieved on June 2, 2007.
African dust outbreaks
In July, the trade winds south of the northward-moving subtropical ridge expand northwestward into Florida. On occasion, dust from the Sahara moving around the southern periphery of the ridge moves into the state, suppressing rainfall and changing the sky from a blue to a white appearance and leading to an increase in red sunsets. Its presence negatively impacts air quality across the Southeastern United States during the summer, by adding to the count of airborne particulates. This is in sharp contrast to the normally clean air over Florida and the southeastern USA, which on average is the cleanest air in the USA.Science Daily. African Dust Called A Major Factor Affecting Southeast U.S. Air Quality. Retrieved on June 10, 2007. Over 50% of the African dust that reaches the United States affects Florida.Science Daily. Microbes And The Dust They Ride In On Pose Potential Health Risks. Retrieved on June 10, 2007. Since 1970, dust outbreaks have worsened due to periods of drought in Africa. There is a large variability in the dust transport to the Caribbean and Florida from year to year.Usinfo.state.gov. Study Says African Dust Affects Climate in U.S., Caribbean. Retrieved on June 10, 2007. Dust events are possibly linked to a decline in the health of coral reefs across the Caribbean and Florida, primarily since the 1970s.U. S. Geological Survey. Coral Mortality and African Dust. Retrieved on June 10, 2007.
Seasonal climate patterns
Winter
On average, Florida has the mildest winters in the continental United States. Average lows range from in Key West to nearly in Tallahassee, while daytime highs range from in Tallahassee to in Miami.Southeast Regional Climate Center. Tallahassee WSO AP Averages from 1948-2005. Retrieved on June 2, 2007.Southeast Regional Climate Center. Key West WSO AP Averages from 1948-2005. Retrieved on June 2, 2007. Predominant tropical easterly winds across central and southern Florida keep temperatures warm during the winter. Occasional strong cold fronts move southward down the peninsula with freezing or near-freezing temperatures on a few nights into inland areas of central Florida every few years. A few times each decade, Miami might see a winter nightfall below . El Niño winters are cooler due to increased cloud cover but have fewer freezes.South Florida Water Management District. El Nino in South Florida. Retrieved on June 2, 2007.
Although rare in south Florida, sub-freezing temperatures can happen and have large impacts. A field experiment in Key Largo Florida found that these cold climates reduced fruit removal by the Key Largo woodrat, slowing down the seed dispersal process most likely caused by these weather conditions.
Five hardiness zones exist. USDA Zone 12A, the warmest zone found within the state, with average extreme annual lows between to , is found in the Dry Tortugas area. USDA Zone 11B, with average annual lows between and , is found between Key West and Marathon. USDA Zone 11A, with average annual lows between and , is found in the remaining Florida Keys, Miami Beach, Homestead, and parts of downtown Miami. USDA Zone 10B, with average annual lows between and , is found in coastal South Florida and much of the Everglades. USDA Zone 10A, with annual average lows between and , is found in the rest of South Florida, and in certain coastal regions as far north as St. Petersburg on the western coast of the state, and roughly Vero Beach on the eastern coast of the state. USDA Zone 9B, with average annual lows between and , is found in interior Central Florida, continuing north towards Fernandina Beach. USDA Zone 9A, with average annual lows between and , is found along an area stretching from Ocala to Pensacola. USDA Zone 8B, the coolest zone found within the state, with average annual lows between and , is located in extreme northwestern Florida along the northern portions of Escambia, Santa Rosa, Okaloosa, Walton, and Holmes counties.
Florida has experienced 12 major freezes. This includes four "impact" freezes, sufficiently severe to kill entire groves of citrus trees, resulting in a noticeable economic impact on citrus growers and prompting them to shift groves further southward. These impact freezes are indicated by asterisks in the following: Great Freeze of 1894-1895*, February 13–14, 1899, February 2–6, 1917, December 12–13, 1934, January 1940, December 12–13, 1957, December 12–13, 1962*, January 18–20, 1977, January 12–14, 1981, December 24–25, 1983*, January 20–22, 1985, and December 22–26, 1989*.
Despite being the mildest on average, the winter climate was a crucial contributing factor of the Challenger disaster on January 28, 1986, in which overnight temperatures at Titusville, adjacent to the Kennedy Space Center, had dropped as low as and were still below freezing at to on launch day. The severe cold had caused the O-Rings on the right-side SRB to crack, as they had only a redline tolerance of
Summer
During the summer, average high temperatures range from near in northern Florida to near in the Keys. Maximum temperatures during the summer average in the higher 90s Fahrenheit statewide.Southeast Regional Climate Center. Historical Climate Summaries for Florida. Retrieved on June 2, 2007. Heat indexes can easily reach . Relief from the heat during the summer comes in the form of afternoon and evening thunderstorm activity, late morning and afternoon sea breezes off the relatively cooler ocean, and during the passage of a tropical cyclone. The record high temperature for the state is at Monticello in 1931.
Fog Like the rest of the Southeastern United States, Florida has a winter maximum in dense fog. Unlike the rest of the region, the maximum in Florida accounts for roughly half of the annual occurrences. Its summer minimum is less than the remainder of the Southeast. The annual number of heavy fog days (with visibility of or less) has ranged from 50 in Tallahassee to 1 in Key West, the least foggy region in the state. The two most common types of fog in Florida are advection and radiational. Fog can be hazardous to early morning commuters. On January 9, 2008, when fog on Interstate 4 combined with smoke from a nearby fire, visibility was reduced to nearly zero. As a result, five individuals died in a 70-car pileup.Gloria Forthun, M. B. Johnson, W. G. Schmitz, and J. Blume.Trends in Fog Frequency and Duration in the Southeast United States. Retrieved on June 7, 2007.Michael Mogil and Kristen L. Seaman. Florida's Climate and Weather. Retrieved on 2012-16-03.
Precipitation
Averages
Statewide, the highest rainfall amounts occur during the summer months. In northern Florida, there is a weak winter secondary maximum while statewide the driest months of the year are during the spring. During El Niño, Florida sees greater rainfall between November and March. Due to the lack of the secondary maximum across the peninsula, a distinct dry season is seen in the averages from winter through spring. This dry season provokes brush fires annually as temperatures rise in late spring, before they fade in early June as the rainy season gets underway.
Extremes
The heaviest rainfall to occur in 24 hours was measured in Yankeetown during Hurricane Easy, . This is also the highest known point storm total maximum related to any tropical cyclone which has impacted Florida,David Roth. Tropical Cyclone Point Maxima. Retrieved on June 2, 2007. and by itself would be the highest known rainfall total for any month from any location within Florida. This rainfall amount remained the national 24-hour rainfall record until Tropical Storm Claudette (1979).David Roth. Hurricane Easy (1950) Rainfall Graphic. Retrieved on June 2, 2007. Heavy rainfall events have fallen due to stalled fronts near the state as well, and occur during the March through May and October through November timeframe.