New Mexico 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 Dust Bowl

North-eastern New Mexico, around Union County, formed the south-western edge of the Dust Bowl. The same pattern applied as elsewhere on the southern Plains: native shortgrass broken for wheat, then a multi-year drought with nothing left to anchor the soil.

Schubert et al. 2004, NCAR/UCAR

Black Sunday, the worst Dust Bowl storm

North-eastern New Mexico sat at the south-western margin of the Black Sunday storm on 14 April 1935. The event is remembered here as the worst day of a decade in which dust, not drought alone, defined life on the southern Plains.

NWS Norman

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

1956 was New Mexico's driest year in this site's 1950-2025 record - 167 mm, 53% below its 1961-90 average. With Arizona, this is the deepest rainfall deficit of any state in the 1950s drought - both states lost over half a normal year's rain.

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

How much ENSO really controls New Mexico's winter rain

Across the fourteen ENSO events in this site's record, New Mexico's winter rainfall followed the index in five of six El Niños and seven of eight La Niñas. The index explains about 22% of the year-to-year variation in New Mexico's December-February rainfall. The extremes: 2009-10 came in +79% against the 1961-90 average, 1999-00 -63%.

NOAA CPC Oceanic Nino IndexENSO 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, New Mexico averaged +1.20°C warmer across 2006-2025 than across the two decades before the Act, 1951-1970, the 17th-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

The 1973-74 La Niña

Globally this was a strong La Niña in the middle of a sustained multi-year cool phase. In New Mexico it showed up as winter rainfall 35% below the 1961-90 average - its 8th-largest ENSO rainfall swing on record.

ONI -2.0°C · RONI -1.9°C

NOAA CPCENSO Tracker

The cold winters of 1976-79

1979 is New Mexico'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.

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 tends to bring the Southwest wetter winters, and the two decades after the 1976-77 flip were among the region's wetter spells of the century - which is part of why the drought that followed the flip back in 1998-99 came as such a contrast.

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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 New Mexico it showed up as winter rainfall 76% above the 1961-90 average - its 2nd-largest ENSO rainfall swing on record.

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

Mount Pinatubo erupts

Pinatubo's cooling is only faintly visible in New Mexico's own record. 1993, two years after the June 1991 eruption, ranks 30th-coldest of the 76 years there, though 1997 has 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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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

Globally this was the strongest El Niño ever measured by the raw ONI index. In New Mexico it showed up as winter rainfall 39% above the 1961-90 average - its 5th-largest ENSO rainfall swing on record.

ONI +2.4°C · RONI +2.3°C

NOAA CPC, NOAA NCEIENSO Tracker

The 1999-2001 La Niña

New Mexico's winter rainfall ran 63% below its 1961-90 average in the 1999-2000 La Niña - its 3rd-largest ENSO rainfall swing on record.

ONI -1.5°C · RONI -1.6°C

NOAA CPC ONI

Pacific Decadal Oscillation flips back to a cool phase

The Pacific Decadal Oscillation flipped back to a cool phase around 1998-99. Cool phases favour dry winters across the Southwest, and the flip coincides with the start of the megadrought in 2000 - natural variability setting the stage, with warming then deepening it.

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Southwest megadrought (2000-2021+)

New Mexico's 2000-2021 rainfall averaged 7% below its 1961-90 average. The megadrought's signature here is less about any single dry year than about the absence of genuinely wet ones to refill the deficit.

Williams et al. 2022

Colorado River flow decline / Lake Mead crisis

New Mexico draws Colorado River water through the San Juan-Chama project, over the continental divide into the Rio Grande basin - so the river's decline compounds a separate problem, the Rio Grande's own drying. Roughly a third to a half of the Colorado's 21st-century flow loss is attributable to higher temperatures alone.

Udall & Overpeck 2017

The 2007-08 La Niña

New Mexico's winter rainfall ran 32% above its 1961-90 average in the 2007-08 La Niña - its 9th-largest ENSO rainfall swing on record.

ONI -1.8°C · RONI -1.7°C

NOAA CPCENSO Tracker

2009-10 El Niño

New Mexico's winter rainfall ran 79% above its 1961-90 average in the 2009-10 El Niño - its largest ENSO rainfall swing on record.

ONI +1.5°C · RONI +1.5°C

NOAA/IRI ENSO archiveENSO Tracker

The 2010-2012 La Niña

New Mexico's winter rainfall ran 46% below its 1961-90 average in the 2010-11 La Niña - its 4th-largest ENSO rainfall swing on record.

ONI -1.6°C · RONI -1.6°C

NOAA CPC ONI

Start of the sustained rise in US heatwave frequency

New Mexico's own Heatwave Days (WSDI) count rose from a 1961-90 average of 3.3 days a year to 25.9 in 2016-25 - more than a sevenfold increase, among the steepest anywhere in the United States.

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

The Wallow Fire

The Wallow Fire crossed from Arizona into western New Mexico in June 2011, part of a fire season in which Texas, New Mexico and Arizona burned together under the same Southern Plains drought. New Mexico's own 2011 was its 6th-driest year in this site's 1950-2025 record.

NASA Earth Observatory, CIRES

The 2012 drought and heat

2012 was New Mexico's 3rd-driest year (214 mm), its 5th-warmest year, and 18.0 heatwave days.

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

Post-2013 acceleration in US temperatures

8 of New Mexico's ten warmest years on record have occurred since 2013, and all ten since 2000, with 2017 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 New Mexico it showed up as winter rainfall 8% below the 1961-90 average - its 14th-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. New Mexico follows closely: eight of its own eleven warmest fall in that span, with 2012, 2003 and 2000 outside. New Mexico's warmest year is 2017.

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The West's air gets drier

New Mexico's relative humidity has fallen 3.5 percentage points comparing 2015-2025 with 1950-2014 - the 3rd-largest fall of any US state - while its annual temperature rose +1.20°C over the same comparison.

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

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 2020-2023 'triple-dip' La Niña

New Mexico's winter rainfall ran 37% below its 1961-90 average in the 2020-21 La Niña - its 7th-largest ENSO rainfall swing on record.

ONI -1.1°C · RONI -1.5°C

WMO, WMO (2)ENSO Tracker

The Rio Grande runs dry through Albuquerque, 2022

A 5-mile stretch went dry for the first time in 40 years, driven by low snowpack and reduced stored water; drying events now occur earlier and farther upstream than in the past.

Washington Post

2023-24 El Niño

Globally this was a strong El Niño, the first since 2015-16. In New Mexico it showed up as winter rainfall 26% above the 1961-90 average - its 11th-largest ENSO rainfall swing on record.

ONI +2.0°C · RONI +1.4°C

NOAA CPCENSO Tracker