New York 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

The Great New England Hurricane of 1938

The 1938 hurricane came ashore on Long Island - which is why it is still known there as the Long Island Express - cutting new inlets through the barrier beaches and destroying hundreds of houses before crossing the Sound into New England.

NWS Boston

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 summer of 1953

1953 gave New York 12.8 heatwave days, its 2nd-highest of the 1950-2025 record, though it ranks only 13th-warmest by annual mean - a summer event, not a warm year. New York City was in the 90s every day from 15 to 21 July and then for twelve consecutive days from 24 August - a record run at the time. 43 New Yorkers died of the heat that year.

Northeast Regional Climate Center, LIFE

The 1962-66 Northeast drought

1964 was New York's driest year in this site's 1950-2025 record - 802 mm, 23% below its 1961-90 average. It was not one dry year but five: 1962-66 as a whole averaged 17% below that baseline. This is New York's drought of record. By late 1964 New York City's reservoirs were down to about a quarter of capacity, and restrictions ran for years.

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

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, New York averaged +1.23°C warmer across 2006-2025 than across the two decades before the Act, 1951-1970, the 13th-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 stalled over the Northeast in June 1972 and put the upper Susquehanna and Chemung rivers into record flood. Elmira and Corning were badly hit - the Corning Museum of Glass flooded to a depth that is still marked on its walls. New York's other defining flood year came in 2011.

USGS

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 New York's winter rainfall - it is not one of the seven states where ENSO reliably moves it. In 1982-83 New York's winter rainfall ran -20% against the 1961-90 average, with temperatures +2.9°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

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 New York's 9th-warmest year in this site's 1950-2025 record, and 1991 its 12th-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 is only faintly visible in New York's own record. 1993, two years after the June 1991 eruption, ranks 18th-coldest of the 76 years there and no year since has been colder. 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 Northeast its reach is through the Atlantic hurricane season: the warm phase since includes Irene in 2011 and Sandy in 2012. 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 New York's winter rainfall ran +31% against the 1961-90 average, with temperatures +4.0°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

The Ice Storm of 1998

The January 1998 ice storm reached across northern New York, hitting the St. Lawrence valley and the Adirondack foothills with days of freezing rain. Maine and Quebec took the most severe accretion.

USDA Forest Service

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 New York's 4th-driest year on record here - 867 mm, 16% below its 1961-90 average.

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

Start of the sustained rise in US heatwave frequency

New York's own Heatwave Days (WSDI) count rose from a 1961-90 average of 3.0 days a year to 6.7 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

The Northeast's record summer of 2010

2010 gave New York more heatwave days than any other year in this site's 1950-2025 record (16.1), alongside its 10th-warmest year overall. The Northeast as a whole had its warmest January-August on record that year, 3.4°F above average.

NOAA Climate.gov, NOAA NCEI, Northeast Regional Climate Center

The floods of 2011

2011 is New York's wettest year in this site's 1950-2025 record - 1,415 mm, 37% above its 1961-90 average and clear of 1996 by 124 mm. Three things did it: spring storms in April and May, Tropical Storm Irene in August, which dropped more than 18 inches on parts of the Catskills, and the remnants of Lee two weeks later, which put over 12 inches into the Susquehanna basin. Federal disaster assistance for the three exceeded $1bn.

SIR 2014-5058, NOAA/NWS, NWS Paducah

Hurricane Sandy (Superstorm Sandy)

The surge reached nearly 14 ft at Lower Manhattan, pushing the Hudson, the East River and New York Harbor into the streets and flooding subway tunnels and the South Ferry station. Sandy arrived at high tide on a full moon, on a coastline where sea level has already risen about a foot since 1900 - which is why a Category 1 at landfall produced a record inundation.

NWS Mount Holly, NJDEP, Britannica

2012: the warmest year on record for the contiguous US

2012 is New York's 2nd-warmest year in this site's 1950-2025 record. Nationally it was the warmest year the contiguous United States had recorded, 3.2°F above the 20th-century average, with a record-warm March that broke more than 15,000 daily records; 19 states set record-warm years.

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

Post-2013 acceleration in US temperatures

5 of New York's ten warmest years on record have occurred since 2013 - fewer than in most states - but 8 of the ten have come since 2000, with 2024 the warmest of all. The acceleration is clear in New York's data; its year-to-year swings are simply wide enough to spread the warmest years further apart than the national mean does.

NOAA Climate at a Glance

2015-16 El Niño

In 2015-16 New York's winter rainfall ran +22% against the 1961-90 average, with temperatures +4.8°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. In New York the pattern is weaker: only five of its eleven warmest fall in that span, with 2012, 2011, 2010, 2006, 1998 and 1990 outside it. Its warmest year is 2024. The warming is in New York's record; it simply arrives in a different order.

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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

The Buffalo blizzard of December 2022

Over the Christmas weekend of 23-27 December 2022 a 'bomb cyclone' brought a flash freeze, gusts over 70 mph and lake-effect snow to western New York. Six to six and a half feet of snow fell on Buffalo's southern suburbs, and the city was paralysed for days. At least 44 people died in the region, many of them found outside in the snow or in stranded cars.

NWS Buffalo, WIVB

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