US Southeast Climate – September 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

The 1950s drought

Among the most widespread and sustained droughts ever recorded in the US - worse than the Dust Bowl in several states. In the Southeast it reached Alabama, Georgia and South Carolina.

NOAA Drought.gov, NOAA Climate Program Office, Texas Water Development Board

How much ENSO really controls the Southeast's winter rain

Of the fifty states, only seven have a December-February rainfall link to El Niño and La Niña strong enough to be worth reporting. Three of them are in the Southeast. Florida is the clearest case in the country - ENSO explains 46% of its winter-rainfall swing, and every one of the fourteen ENSO events in this record moved it the way the index predicted - with Georgia at 19% and South Carolina at 16%. Alabama, North Carolina and Virginia fall below the line.

NOAA CPC Oceanic Nino IndexENSO Tracker

The summer of 1953

One of the most widespread hot summers in the US record: a top-five heatwave year in 23 states. In the Southeast that included Virginia, where it is the 2nd-highest heatwave year on record.

Northeast Regional Climate Center, LIFE

The 1955-56 La Niña

One of the strongest La Niñas since instrument-based ENSO records begin in 1950, and part of a run of cool Pacific years through the mid-1950s. La Niña cools global temperatures slightly for a year or two while it lasts, and shifts rainfall patterns worldwide.

ONI -1.6°C · RONI -1.4°C

NOAA CPCENSO Tracker

The 1962-66 drought

Centred on the Northeast, the 1962-66 drought was the longest and most severe on the books there, and New York City's reservoirs fell to about a quarter of capacity. It also reached Virginia, where 1965 is the driest year in this site's 1950-2025 record.

USGS, Seager et al. 2012, NYC Emergency Management

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

Hurricane Camille

One of only four Category 5 hurricanes ever to strike the continental US. In the Southeast its remnants hit Virginia, where flash floods centred on Nelson County killed 113 people.

NWS Mobile, Mississippi Encyclopedia, Encyclopedia Virginia

US Clean Air Act

The 1970 Clean Air Act cut sulphur dioxide and particulate pollution across the country, and removing those sunlight-reflecting aerosols also removed a cooling effect that had been partly masking greenhouse warming. Across the Southeast, 2006-2025 averaged +1.08°C warmer than the two decades before the Act, 1951-1970.

US EPA

The 1972-73 El Niño

One of the strongest El Niños on record. It contributed to failed grain harvests in the Soviet Union and elsewhere in 1972, and to a sharp rise in world food prices - an early sign of how far ENSO's reach extends.

ONI +1.8°C · RONI +2.0°C

NOAA CPCENSO Tracker

Hurricane Agnes

The most destructive hurricane in US history at the time. In the Southeast it hit Virginia.

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

The strongest La Niña of the 1950-present record, part of a multi-year cool phase that also included a second, separate La Niña in 1975-76.

ONI -2.0°C · RONI -1.9°C

NOAA CPCENSO Tracker

The cold winters of 1976-79

Three severe winters in a row. January 1977 was probably the coldest month the eastern United States had seen in two centuries - Atlanta's coldest month ever measured - and the winter of 1978-79 was the coldest on record for the contiguous United States. Missouri had its coldest winter on record; Illinois had its coldest January-February, 14°F below normal, with seventeen major winter storms.

Illinois State Water Survey, Missouri Climate Center, Monthly Weather Review (1978), Wikipedia

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.

Learn more →

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

El Niño usually brings the Southeast a wet winter. In 1982-83 it was: winter rainfall ran +23% against the 1961-90 average, with temperatures +0.8°C. On NOAA's RONI index, which strips out background ocean warming, this is the strongest El Niño since 1950.

ONI +2.1°C · RONI +2.4°C

NOAA CPC, NOAA CPC (2)ENSO Tracker

The 1988-89 La Niña

One of the strongest La Niñas on record, arriving directly after the 1986-87 El Niño. For the United States it matters as a cause rather than a curiosity: it is a major driver of the 1988 Midwest drought and the Yellowstone fires of that summer. La Niña tends to push the jet stream north, leaving the central and southern US hot and dry.

ONI -1.9°C · RONI -1.9°C

NOAA CPCENSO Tracker

Hurricane Hugo

A Category 4 landfall near Charleston that produced the highest storm tide ever recorded on the US East Coast. It hit South Carolina and North Carolina.

NWS Charleston, Charleston County Public Library

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

Mild winters made 1990 the 7th-warmest year then recorded in the contiguous United States, and the 4th-warmest in the Northeast. January-February 1990 set the national record for those months, which stood until 1998, and 1991 was nearly as warm across much of the East.

News & Record / AP (1991), NOAA NCEI

Mount Pinatubo erupts

Pinatubo's cooling is only faintly visible in the Southeast's own record. 1993, two years after the June 1991 eruption, ranks 29th-coldest of the 76 years there, though 1996, 1997, 2010 and 2014 have since been colder. A single large eruption can hold temperatures down for two or three years; it cannot reverse the trend.

Learn more →

Hurricane Andrew

A Category 5 landfall on south Florida, and the most expensive US natural disaster until Katrina.

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.

Learn more →

1997-98 El Niño

El Niño usually brings the Southeast a wet winter. In 1997-98 it was: winter rainfall ran +64% against the 1961-90 average, with temperatures +1.7°C. It is often treated as the textbook strong El Niño.

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.

Learn more →

The 1999-2002 Eastern drought

A multi-year drought down the eastern seaboard, at its worst in 2001-02. In the Southeast, 2001 is the 2nd-driest year on record in North Carolina and South Carolina, and the 3rd-driest in Virginia.

USGS New England Water Science Center, Vermont State Climate Office, NOAA Drought.gov

The south Georgia tornadoes of February 2000 (Camilla)

Late on 13 February 2000 and into Valentine's Day, three strong night-time tornadoes crossed south-west Georgia, killing 19 people - 11 in and around Camilla, where an F3 tore through two subdivisions and four mobile home parks. Around 200 homes were destroyed. It was south Georgia's deadliest tornado event in nearly 50 years.

NWS Tallahassee, NOAA NCEI Storm Events

The wet year of 2003

One of the wettest years on record across the Mid-Atlantic, ranking 2nd in Maryland, Virginia and West Virginia. In the Southeast it is also the 3rd-wettest year on record in North Carolina.

NOAA NCEI

Hurricane Katrina

The costliest US hurricane of its time, with 520 direct deaths. In the Southeast it hit Alabama and Florida.

NOAA NHC, NWS Mobile, Climate Signals

The 2006-08 Southeast drought

The driest year on record in North Carolina and Tennessee, and the drought that took Atlanta's Lake Lanier to record lows. It reached Alabama, Florida, Georgia, North Carolina and South Carolina.

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

The September 2009 Atlanta floods

A 500-year flood across metro Atlanta that broke records more than a century old.

USGS, NWS Peachtree City

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

Across the six states of the Southeast, Heatwave Days (WSDI) rose from a 1961-90 average of 6.2 days a year to 12.3 in 2016-25 - a rise of 99%, with every one of them recording more heatwave days than in 1961-90. It is not uniform: Florida is at 2.5x, South Carolina at 1.4x.

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

2011 Super Outbreak (Tuscaloosa-Birmingham)

62 tornadoes in 24 hours (a state record), 243 Alabama deaths - the deadliest single-day tornado toll for the state, part of a 368-tornado, 3-day national outbreak.

NOAA NCEI

2012: the warmest year on record for the contiguous US

2012 was the warmest year ever recorded for the contiguous United States, 3.2°F above the 20th-century average and a full 1.0°F above the previous record, 1998. March 2012 was the warmest March on record, breaking more than 15,000 daily records, and 19 states had their warmest year.

NOAA Climate.gov, NOAA Climate.gov (2)

Post-2013 acceleration in US temperatures

Across the six states of the Southeast, an average of 7.0 of each state's ten warmest years have come since 2013, ranging from 6 in South Carolina to 8 in Florida. Every state in the region has at least 8 of its ten warmest since 2000.

NOAA Climate at a Glance

2015-16 El Niño

El Niño usually brings the Southeast a wet winter. In 2015-16 it was: winter rainfall ran +32% against the 1961-90 average, with temperatures +2.7°C. By the raw ONI index it was the strongest El Niño ever measured - a reminder that a strong index does not guarantee a strong local outcome.

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. The Southeast follows it closely: eight of its own eleven warmest fall in that span, with 2012, 1998 and 1990 outside it. Its warmest year is 2019.

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South Carolina's October 2015 'thousand-year' flood

NOAA Atlas 14 classified the rainfall (10-26in+ over 5 days) as a 1-in-100 to 1-in-1000-year event for parts of the state - a stalled front plus tropical moisture from Hurricane Joaquin. 19 deaths, ~50 dams failed.

NOAA Climate.gov

Nights warm faster than days in the South-East US

The clearest regional signal in US data of nights warming faster than days. It shows in Alabama, Florida, Georgia, North Carolina and South Carolina.

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

2018: the wettest year on record across the East

The year nine eastern states all set their wettest year on record. Two of them are in the Southeast: North Carolina and Virginia.

NOAA NCEI, NOAA Climate.gov, NOAA NESDIS

Hurricane Florence

Florence came ashore near Wrightsville Beach on 14 September 2018 and then barely moved, which is what made it a flood rather than a wind event. A station near Elizabethtown recorded 35.93 inches - a North Carolina tropical-cyclone rainfall record that beat Hurricane Floyd's 24.06 inches from 1999 by nearly a foot. 2018 finished as North Carolina's wettest year in this site's 1950-2025 record.

North Carolina State Climate Office, NWS Wilmington

Hurricane Michael

One of only four Category 5 hurricanes ever to make landfall in the continental United States. It came ashore on the Florida Panhandle.

NOAA NHC, NOAA

The 2019 flash drought

A flash drought that took the share of the Southeast in drought from 25% to 80% in a single month. It reached every state in the Southeast.

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

A rapidly intensifying Category 4 whose rainfall was about 18% heavier because of human-caused warming. It came ashore in south-west Florida.

NOAA NHC, World Weather Attribution

2023-24 El Niño

A strong El Niño arriving on top of long-term greenhouse warming, with the cut in shipping sulphur from the 2020 fuel rule adding a little more. Together they produced the record global temperatures of 2023 and 2024.

ONI +2.0°C · RONI +1.4°C

NOAA CPCENSO Tracker

Hurricane Helene

The deadliest hurricane to strike the US mainland since Katrina, with most of its 250+ deaths hundreds of miles inland. It hit Florida, Georgia, North Carolina and South Carolina.

NOAA Climate.gov, World Weather Attribution