North Carolina 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

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, North Carolina averaged +1.11°C warmer across 2006-2025 than across the two decades before the Act, 1951-1970, against a median of +1.09°C across the 49 states whose records reach back that far. Every one of them warmed. The range runs from +0.66°C in Oklahoma to +1.67°C in Alaska, so the question a state's own chart answers is not whether it warmed, but by how much.

US EPA

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

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

El Niño has only a weak pull on North Carolina's winter rainfall - it is not one of the seven states where ENSO reliably moves it. In 1982-83 North Carolina's winter rainfall ran +20% against the 1961-90 average, with temperatures +1.0°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

Hurricane Hugo

Hugo is unusual for how little it weakened inland. After a Category 4 landfall near Charleston on 22 September 1989 it was still producing hurricane-force gusts over Charlotte, roughly 200 miles from the coast, causing severe damage across the North Carolina Piedmont - far from where a hurricane's damage is normally expected.

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

1990 is North Carolina's 3rd-warmest year in this site's 1950-2025 record, and 1991 its 14th-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 North Carolina's own record: 1993, two years after the June 1991 eruption, was an unremarkable year there, 35th-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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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

In 1997-98 North Carolina's winter rainfall ran +58% against the 1961-90 average, with temperatures +2.0°C - though ENSO's pull on rainfall here is weak. 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.

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The 1999-2002 Eastern drought

2001 was North Carolina's 2nd-driest year on record here - 960 mm, 23% below its 1961-90 average. It was not one dry year: 2001 and 2002 together averaged 13% below that baseline.

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

The wet year of 2003

2003 was North Carolina's 3rd-wettest year in this site's 1950-2025 record - +28% against its 1961-90 average. It is one of three exceptionally wet years the Mid-Atlantic has had this century, alongside 2018 and 2020.

NOAA NCEI

The 2006-08 Southeast drought

2007 is North Carolina's driest year in this site's 1950-2025 record - 29% 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. Water restrictions ran across the Piedmont and several towns came within weeks of exhausting their supply.

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

Start of the sustained rise in US heatwave frequency

North Carolina's own Heatwave Days (WSDI) count rose from a 1961-90 average of 4.7 days a year to 6.9 in 2016-25 - a modest rise, and one of the smallest in the country against a 50-state average of 2.4x.

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

Post-2013 acceleration in US temperatures

7 of North Carolina's ten warmest years on record have occurred since 2013, and 8 of the ten since 2000, with 2019 the warmest of all.

NOAA Climate at a Glance

2015-16 El Niño

In 2015-16 North Carolina's winter rainfall ran +38% against the 1961-90 average, with temperatures +2.9°C - though ENSO's pull on rainfall here is weak. 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. North Carolina's own record is a looser fit - seven of its eleven warmest fall in that span, with 2012, 2007, 1998 and 1990 outside it. Its warmest year is 2019.

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Nights warm faster than days in the South-East US

North Carolina's nights have warmed far faster than its days. Against the 1950-2014 average, the 2015-2025 period runs +1.37°C on overnight minimum temperature but only +0.84°C on daytime maximum - nights warming roughly 1.6 times as fast. The gap between day and night has closed by 0.53°C, the 8th-largest narrowing of any US state.

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

2018: the wettest year on record across the East

2018 was North Carolina's wettest year in this site's 1950-2025 record - 1736 mm, 39% above its 1961-90 average and ahead of second-placed 2020 (1690 mm), which has since come closest to it. North Carolina's 68.36 in beat its 2003 record by more than five inches - though here the year is inseparable from Hurricane Florence in September.

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

The 2019 Southeast flash drought

2019 gave North Carolina more heatwave days than any year in this site's 1950-2025 record (25.2), and its warmest year overall. September 2019 was among the driest on record here. The year as a whole was not dry at all here - 49th-driest of 76, so in the wetter half of the record. A month of heat did the damage, and the annual total never shows it.

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

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

North Carolina took the worst of Helene, five hundred miles from where it made landfall. More than 30 inches of rain fell on parts of the west of the state; in Asheville the French Broad River passed its 1916 flood record by over a foot and a half, mountain towns and the roads and rail to them were washed away, and the pipes carrying water down from the treatment plants were severed. 107 North Carolinians died. Asheville had been described for years as a 'climate haven' - inland, elevated, somewhere to move to escape climate risk.

NOAA Climate.gov, World Weather Attribution