US Records Unprecedented Heat in March as El Niño Looms

The continental United States experienced its most abnormally hot month in 132 years of record-keeping this March, according to federal weather data released Wednesday by the National Oceanic and Atmospheric Administration (NOAA).

March’s average temperature reached 50.85 degrees Fahrenheit (10.47 degrees Celsius), a staggering 9.35 degrees F (5.19 C) above the 20th century normal for the month. This surpassed the previous record of 8.9 degrees F set in March 2012 as the most abnormally hot month in US history, regardless of which month of the year.

Daytime temperatures were particularly extreme, with March’s average maximum temperature soaring 11.4 degrees F (6.3 C) above the 20th century average—nearly a degree warmer than the typical daytime high for April.

“What we experienced in March across the United States was unprecedented,” said Shel Winkley, a meteorologist with Climate Central, a nonprofit science research group. “One reason that’s so concerning is just the sheer volume of all-time records that were set and broken during that period.”

This extreme heat follows what was already the worst snow year and hottest winter on record, creating a troubling pattern. The 12-month period from April 2025 to March 2026 now stands as the warmest such period ever recorded in the continental United States.

The March heat wave shattered more than 19,800 daily temperature records nationwide, according to meteorologist Guy Walton’s analysis of NOAA data. More than 2,000 locations set monthly heat records—which are significantly harder to break than daily records. That’s more March heat records set in a single month than in entire previous decades.

Climate Central calculated that on March 20-21 alone, about one-third of the nation experienced unseasonable heat that would have been virtually impossible without human-caused climate change.

“January through March was also the driest on record for the contiguous U.S.,” noted meteorologist Jeff Masters of Yale Climate Connections. “Not only was it hot, it was record dry as well. And that’s a bad combination for water availability, for agriculture, for river levels, and for navigation.”

More concerning is what meteorologists see on the horizon. Both the European climate and weather service Copernicus and NOAA are forecasting a “super” strong El Niño to form in the coming months, likely intensifying through winter. This natural climate phenomenon could push global temperatures even higher, potentially surpassing the record set in 2024.

An El Niño forms when parts of the central Pacific Ocean become abnormally warm, altering weather patterns worldwide. It’s considered moderate at 1 degree Celsius (1.8 F) above normal and strong at 1.5 degrees. Both NOAA and European forecasters predict this upcoming El Niño will exceed 2 degrees Celsius—putting it in “super” territory and potentially rivaling records set in 2015-2016.

“A strong El Niño could plausibly push global temperatures to new record levels in late 2026 and into 2027,” said Victor Gensini, meteorology professor at Northern Illinois University. El Niños release heat stored in the upper ocean into the atmosphere, raising global temperatures with a lag time of several months.

Super-sized El Niños can trigger what scientists call a “climate regime shift,” altering normal weather patterns for years or even decades. A study published last December in Nature Communications found that after the 2015-2016 El Niño, the Gulf of Mexico shifted to a sustained higher temperature level, potentially contributing to stronger hurricanes along the Gulf Coast in subsequent years.

Growing research indicates that climate change from burning fossil fuels may be intensifying El Niño events, though scientists say this isn’t yet fully established.

“Global warming is supercharging El Niños and the atmospheric warming they drive,” said Jonathan Overpeck, environment dean and climate scientist at the University of Michigan. “We saw this in 2016 and more recently in 2023. We’re likely to see another jump in global temperatures if a strong El Niño develops later this year as predicted.”

While El Niño typically reduces hurricane activity in the Atlantic, it tends to increase Pacific storms and could help alleviate drought conditions in the American Southwest.