Florida Climate – Sep 2026September 2026 Update

Novarupta (Katmai) eruption

The largest volcanic eruption anywhere in the world in the 20th century - 13 km3 of magma, about thirty times the 1980 Mount St. Helens eruption - at Novarupta in Alaska on 6-8 June 1912. Ash reached 100,000 ft and cooled the Northern Hemisphere by roughly 0.3°C over 1912-13. Unlike a tropical eruption such as Pinatubo, a high-latitude eruption's haze stays in its own hemisphere, so it did little to the Southern Hemisphere.

Smithsonian Global Volcanism Program, Alaska Volcano Observatory, National Park Service, Oman et al. 2005

Post-WWII industrial expansion begins

After the Second World War, coal and oil use grew rapidly across Europe, North America and the Soviet Union. Global sulphur dioxide emissions rose from about 30 to about 130 million tonnes a year by 1980, and the sulphate haze they formed masked part of the greenhouse warming underneath - the effect known as 'global dimming'.

Klimont et al. 2013

How much ENSO really controls Florida's winter rain

Of the fourteen ENSO events in this site's record, Florida's winter rainfall followed the index in every single one - six El Niños wet, eight La Niñas dry. The index explains about 46% of the year-to-year variation in Florida's December-February rainfall. The extremes: 1997-98 came in +112% against the 1961-90 average, 1988-89 -56%.

NOAA CPC Oceanic Nino IndexENSO Tracker

The 1955-56 La Niña

Florida's winter rainfall ran 35% below its 1961-90 average in the 1955-56 La Niña - its 7th-largest ENSO rainfall swing on record.

ONI -1.6°C · RONI -1.4°C

NOAA CPCENSO Tracker

Agung eruption

Agung's eruption in Bali put a veil of sulphate haze into the stratosphere that cooled global temperature by about 0.3°C over 1963-66.

Smithsonian Global Volcanism Program, NOAA Global Monitoring Laboratory

US Clean Air Act

The 1970 Clean Air Act set strict national standards for sulphur dioxide and particulates, and American skies got measurably cleaner over the decades that followed. There is a climate sting in that success: sulphate aerosols reflect sunlight, so removing them removed a cooling effect that had been partly masking greenhouse warming. Measured here, Florida averaged +1.21°C warmer across 2006-2025 than across the two decades before the Act, 1951-1970, the 14th-largest rise of the 49 states measured and above their median of +1.09°C. Cleaning the air was right for human health. It also uncovered warming that was already there.

US EPA

Hurricane Agnes

Agnes made its first landfall on the Florida panhandle on 19 June 1972 as a weak hurricane, bringing tornadoes and moderate flooding but little of the damage it would go on to cause. Its catastrophe happened days later and a thousand miles north, when it stalled over the Mid-Atlantic - a reminder that where a hurricane comes ashore and where it does its harm are often different places.

USGS

South East Florida's accelerating sea-level rise

NOAA tide-gauge analysis shows the rate accelerating from 3.1mm/yr (1972-2022) to 5.9mm/yr (since 1993) to 8.2mm/yr (since 2003) - among the fastest acceleration on the US coast.

Florida Climate Center / FSU

The 1973-74 La Niña

Globally this was a strong La Niña in the middle of a sustained multi-year cool phase. In Florida it showed up as winter rainfall 21% below the 1961-90 average - its 10th-largest ENSO rainfall swing on record.

ONI -2.0°C · RONI -1.9°C

NOAA CPCENSO Tracker

Pacific Decadal Oscillation flips to a warm phase

The Pacific Decadal Oscillation is a North Pacific pattern, and its influence on this side of the country is weak and indirect - mostly through how it nudges the winter jet stream downstream. Its 1976-77 flip marks a genuine shift in Pacific-basin climate, but for eastern states the Atlantic Multidecadal Oscillation is the ocean cycle that matters more.

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Global SO2 emissions peak

Global sulphur dioxide emissions peak at about 130 million tonnes a year, then begin a long decline as Europe, North America and Japan clean up their air. As the aerosol mask thins, the rate of global warming picks up through the 1980s.

Klimont et al. 2013

El Chichón eruption

A sulphur-rich eruption in Mexico whose aerosol cloud stayed in the stratosphere for more than two years, cooling the Northern Hemisphere by about 0.2°C.

Smithsonian Global Volcanism Program

1982-83 El Niño

Globally this was the strongest El Niño since 1950 on NOAA's RONI index, which strips out background ocean warming. In Florida it showed up as winter rainfall 51% above the 1961-90 average - its 3rd-largest ENSO rainfall swing on record.

ONI +2.1°C · RONI +2.4°C

NOAA CPC, NOAA CPC (2)ENSO Tracker

The 1988-89 La Niña

Florida's winter rainfall ran 56% below its 1961-90 average in the 1988-89 La Niña - its 2nd-largest ENSO rainfall swing on record.

ONI -1.9°C · RONI -1.9°C

NOAA CPCENSO Tracker

Daytime warming catches up with the night-led pattern

Across 1961-90, 81% of the world's land saw nights warming faster than days. Across 1991-2020 the pattern reversed: 70% saw days warming faster, as the industrial haze that had been dimming daytime sunshine was cleaned up. The study compares two fixed thirty-year windows; measured as a turning point, this site's own global series turns around 1982.

Zhong et al. 2023

1990-91: mild winters and warm years

1990 is Florida's 8th-warmest year in this site's 1950-2025 record, and 1991 its 15th-warmest. Mild winters did most of it: January-February 1990 was the warmest start to a year the contiguous US had recorded, a record that stood until 1998.

News & Record / AP (1991), NOAA NCEI

Mount Pinatubo erupts

Pinatubo's cooling does not show in Florida's own record: 1993, two years after the June 1991 eruption, was an unremarkable year there, 32nd-coldest of 76. A single large eruption can hold temperatures down for two or three years; it cannot reverse the trend.

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Hurricane Andrew

Andrew crossed Elliott Key and came ashore at Homestead on 24 August 1992 as a Category 5 - one of only a handful ever to strike the United States at that intensity. It destroyed more than 63,500 houses in south Florida and damaged over 124,000. The rebuilding exposed how weakly the area had been built, and produced the Florida Building Code, now among the strictest wind standards anywhere in the world.

NOAA NESDIS, National Park Service

Atlantic Multidecadal Oscillation flips to a warm phase

The Atlantic Multidecadal Oscillation flipped to a warm phase in 1995, and for the Southeast that has meant a more active hurricane season: the warm phase since includes Florence and Michael in 2018 and Helene in 2024. It is a natural cycle of roughly 60-70 years, so it shifts the baseline rather than driving the long-term trend.

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1997-98 El Niño

Globally this was the strongest El Niño ever measured by the raw ONI index. In Florida it showed up as winter rainfall 112% above the 1961-90 average - its largest ENSO rainfall swing on record.

ONI +2.4°C · RONI +2.3°C

NOAA CPC, NOAA NCEIENSO Tracker

Pacific Decadal Oscillation flips back to a cool phase

The Pacific Decadal Oscillation returned to a cool phase around 1998-99. Its direct effects are western - drier conditions across the south-west, changes in North Pacific fisheries - and its influence on this side of the country is weak and indirect. The Atlantic Multidecadal Oscillation, which flipped warm in 1995, is the ocean cycle with more bearing on eastern weather.

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Hurricane Katrina

Florida saw Katrina first, not last. It came ashore near Hallandale Beach on 25 August 2005 as a Category 1, killed 6 people, crossed the peninsula, and then spent two days over an unusually warm Gulf of Mexico - which is where it became the Category 5 that went on to devastate Louisiana and Mississippi.

NOAA NHC, NWS Mobile, Climate Signals

The 2006-08 Southeast drought

2006 was Florida's 2nd-driest year on record here - 22% below its 1961-90 average - and the same year its lowest relative humidity of any year in that record. The two go together: parched ground and dried-out vegetation stop returning moisture to the air, so the humidity that normally hangs over the south-east simply was not there. Florida's drought started earliest: Key West went 175 days from 22 November 2005 to 14 May 2006 on 1.05 inches of rain against a normal 11.80 - the driest stretch ever recorded there - and 2006 and 2007 were south Florida's driest back-to-back calendar years since records began in 1932.

NWS, NWS Key West, Florida BRACE, Florida Climate Center

Florida's January 2010 cold snap

For nearly a fortnight in January 2010 temperatures across the south Florida wetlands sat close to 30°F. West Palm Beach dropped into the 30s on nine nights between the 2nd and the 13th, and Miami fell to 35°F, breaking a daily record set in 1909. Iguanas dropped out of trees. More than 900 manatees crowded into the warm water at Blue Spring, against fewer than 70 a week earlier, and there were mass die-offs of fish, sea turtles, crocodiles and coral. The cause was a strongly negative Arctic Oscillation that winter - a weakened polar vortex letting Arctic air spill unusually far south. 2010 is Florida's 6th-coldest year in this site's 1950-2025 record.

NOAA/phys.org, AccuWeatherPolar Vortex Tracker

Start of the sustained rise in US heatwave frequency

Florida's own Heatwave Days (WSDI) count rose from a 1961-90 average of 7.2 days a year to 18.0 in 2016-25 - more than doubling, close to the 2.4x averaged across the 50 states.

World Bank CCKP (CCKP), NOAA Climate at a Glance

Post-2013 acceleration in US temperatures

8 of Florida's ten warmest years on record have occurred since 2013, and 8 of the ten since 2000, with 2015 the warmest of all - a local acceleration closely tracking the national one.

NOAA Climate at a Glance

2015-16 El Niño

Globally this was tied with 1997-98 as the strongest on the raw ONI index. In Florida it showed up as winter rainfall 33% above the 1961-90 average - its 8th-largest ENSO rainfall swing on record.

ONI +2.6°C · RONI +2.3°C

NOAA CPCENSO Tracker

2015-2025: the eleven warmest years on record

Globally, the eleven warmest years on record have all happened since 2015. Florida tracks that closely - nine of its own eleven warmest fall in the same span, with only 1998 and 1990 outside. Florida and California are the closest-matching states in the country, and Florida's warmest year is 2015.

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Nights warm faster than days in the South-East US

Florida's nights have warmed far faster than its days. Against the 1950-2014 average, the 2015-2025 period runs +1.60°C on overnight minimum temperature but only +0.98°C on daytime maximum - nights warming roughly 1.6 times as fast. The gap between day and night has closed by 0.61°C, the 3rd-largest narrowing of any US state.

NOAA Climate at a Glance, World Bank CCKP (CCKP)

Hurricane Michael

Michael came ashore near Mexico Beach on 10 October 2018 with sustained winds of 161 mph - a Category 5, the first to make landfall in the United States since Andrew in 1992 and only the fourth on record. Storm surge of 9 to 14 ft inundated the coast from Mexico Beach to Indian Pass, with waves destroying the second storeys of buildings. 16 direct deaths and about $25bn of damage.

NOAA NHC, NOAA

The 2019 Southeast flash drought

2019 gave Florida its 3rd-highest heatwave-day count of the 1950-2025 record (24.2), and its 4th-warmest year. September 2019 was Florida's driest September in records back to 1895. The year's rainfall still finished mid-table, 29th-driest of 76 - a drought this sharp can come and go without moving the annual figure.

NOAA Climate.gov, NOAA NCEI, Wang et al. 2021

Low-sulphur shipping fuel rule (IMO 2020)

New international shipping rules cut the sulphur allowed in ship fuel from 3.5% to 0.5% almost overnight, removing about 8 million tonnes of sulphur dioxide a year. With less sulphate haze over the oceans, it may have added around 0.1°C of warming by 2023-24.

Gettelman et al. 2024

Hurricane Ian

Ian came ashore in south-west Florida on 28 September 2022 at 150 mph, a high-end Category 4, after rapidly intensifying - packing two days' worth of strengthening into less than 36 hours. Attribution analysis found its rainfall about 18% heavier than it would have been without human-caused warming.

NOAA NHC, World Weather Attribution

2023-24 El Niño

Globally this was a strong El Niño, the first since 2015-16. In Florida it showed up as winter rainfall 21% above the 1961-90 average - its 11th-largest ENSO rainfall swing on record.

ONI +2.0°C · RONI +1.4°C

NOAA CPCENSO Tracker

Hurricane Helene

Helene came ashore in the Florida panhandle on 26 September 2024 as a Category 4 with sustained winds near 140 mph, bringing storm surge to the Big Bend coast. Florida took the landfall; the great majority of the deaths happened hundreds of miles inland, in the southern Appalachians.

NOAA Climate.gov, World Weather Attribution