North Dakota 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

The 1952 Northwest drought

1952 was North Dakota's 2nd-driest year on record here - 308 mm, 30% below its 1961-90 average. This is a north-western drought, separate from the great 1950s drought of the Southern Plains that ran through the same decade.

NOAA NCEI

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 Dakota averaged +1.02°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

The 1976-77 drought

1976 was North Dakota's 3rd-driest year on record here - 312 mm, 29% below its 1961-90 average.

USGS, US GAO, USGS Water Data Labs

The cold winters of 1976-79

1979 is North Dakota's 4th-coldest year in this site's 1950-2025 record. Its first months were the end of the winter of 1978-79, the coldest on record for the contiguous United States and the third brutal winter in a row across the Midwest.

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

Pacific Decadal Oscillation flips to a warm phase

A warm Pacific Decadal Oscillation pushes the winter storm track north of the northern Rockies and Plains, tending to bring milder winters and lighter snowpack. The 1976-77 flip began about two decades of that phase.

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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 Dakota's winter rainfall - it is not one of the seven states where ENSO reliably moves it. In 1982-83 North Dakota's winter rainfall ran -12% against the 1961-90 average, with temperatures +5.3°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

1988 Midwest drought / Yellowstone fires

1988 was North Dakota's driest year in this site's 1950-2025 record (290 mm, 34% below its 1961-90 average) with its highest heatwave-day count on record at 42.1. Drought and heat peaked together here: no other year in the record is both.

NOAA

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 Dakota's 11th-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 aerosol veil left a clear mark on North Dakota. 1993, two years after the June 1991 eruption, is North Dakota's 12th-coldest year of the 76 on record, though 1996 and 2019 have since been colder. A single large eruption can hold temperatures down for two or three years; it cannot reverse the trend.

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The Great Flood of 1993 (Mississippi River)

1993 was North Dakota's 4th-wettest year in this site's 1950-2025 record - 583 mm, 33% above its 1961-90 average.

NASA Earth Observatory / NWS

Atlantic Multidecadal Oscillation flips to a warm phase

The Atlantic Multidecadal Oscillation flipped to a warm phase in 1995. It is an Atlantic cycle, but its reach is not confined to the coast: a warm AMO alongside a cool Pacific has been tied to more frequent drought across the western and central United States, including the widespread droughts of 1996 and 1999-2002. 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 Dakota's winter rainfall ran +54% against the 1961-90 average, with temperatures +5.7°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 1997 Red River flood (Grand Forks)

The most severe Red River flood since 1826 - Grand Forks/East Grand Forks evacuated ~90% of their population, the largest US city evacuation since the Civil War at the time. $3.5bn damage.

NOAA CPC

Pacific Decadal Oscillation flips back to a cool phase

The Pacific Decadal Oscillation flipped back to a cool phase around 1998-99, which tends to favour colder, snowier winters across the northern Rockies and Plains.

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2006: a national heat record that lasted six years

2006 is North Dakota's 4th-warmest year in this site's 1950-2025 record. It was the warmest year ever recorded for the contiguous United States at the time, beating the 1998 El Niño record - and it has since been pushed down to 10th nationally, passed by nine warmer years in under two decades.

NOAA NCEI, Science

Start of the sustained rise in US heatwave frequency

North Dakota's own Heatwave Days (WSDI) count rose from a 1961-90 average of 8.5 days a year to 14.0 in 2016-25 - a clear rise, though more moderate than the 2.4x averaged across the 50 states.

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

The 2012 drought and heat

2012 was North Dakota's 3rd-warmest year and its 7th-highest for heatwave days, so the heat reached this far north - but rainfall finished 15th-driest of 76, short of the state's own dry extremes. The worst of the drought that made 2012 notorious nationally sat further south, over the central Plains and Corn Belt.

NOAA NCEI, Summer 2012 Drought Update, NOAA NCEI, Drought

Post-2013 acceleration in US temperatures

4 of North Dakota's ten warmest years on record have occurred since 2013 and 6 of the ten since 2000, so the clustering is there - but North Dakota is the one state whose single warmest year on record (1987) still predates 2000, a reminder that one hot year is not the same thing as a trend.

NOAA Climate at a Glance

2015-16 El Niño

In 2015-16 North Dakota's winter rainfall ran -15% against the 1961-90 average, with temperatures +5.3°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 Dakota is the exception - its hottest year is still 1987, the only state whose warmest year predates 2000, and just four of its eleven warmest fall in that span.

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2019: the wettest year across the Upper Midwest

2019 was North Dakota's wettest year in this site's 1950-2025 record - 620 mm, 41% above its 1961-90 average. In a state whose normal annual rainfall is under half Wisconsin's, that surplus left fields unworkable and a large share of the crop unplanted.

Wisconsin State Climatology Office / WPR, Midwestern Regional Climate Center, NWS Green Bay

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