Over 400 records broken as historic heatwave roasts more than 40M across the West with dangerous temperatures
An unprecedented March heat wave is underway from California across the Southwest, to parts of the Great Plains, setting new high temperature records, with conditions running as much as 35 degrees above average for this time of year.
An unprecedented March heat wave is underway from California across the Southwest, to parts of the Great Plains, setting new high temperature records, with conditions running as much as 35 degrees above average for this time of year.
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More than 40 million people across Southern California and the deserts of Arizona and New Mexico are under Extreme Heat Warnings and Heat Advisories through Sunday.
The early scorching temperatures are also expected to further deplete the snowpacks across western mountain ranges — many of which were already running significant deficits after a winter with little snow. These snowpacks are a critical water source for many communities during the summer.
The hottest days are expected to be Thursday through Saturday, but relief will not be immediate.
After the heat arrived Monday, Tuesday brought at least 47 new daily records to California and Oregon.
Phoenix rose to 102 degrees Wednesday, becoming the earliest date the city has reached the century mark. Parts of California also reached triple digits as the heat wave intensified.
More than 400 record highs have been set since Mar. 11, with dozens more expected to be shattered through next week, the FOX Forecast Center said.
The hottest all-time March temperature in California was tied Wednesday afternoon as the community of Themal in the Coachella Valley reached 107 degrees.
In particular, several locations across Southern California broke both their all-time March high temperature record and their daily record highs.
Phoenix is expected to climb to 106 degrees Friday.
The FOX Forecast Center said even after Saturday, the heat will linger, with some places potentially breaking daily temperature records for seven days straight, a rare occurrence.
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Not only will daily temperature records continue to break, but monthly records will likely be shattered by a large margin.
Palm Springs, California, is forecast to reach 108 degrees on Friday. If it happens, this will not only be the hottest March day Palm Springs has ever seen, but it will tie the U.S. record high for the month of March set in Rio Grande City in 1954 and Falcon Dam, Texas in 2020.
People across coastal California have flocked to beaches to take advantage of the unusual extra warmth.
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San Francisco's Department of Emergency Management reminded residents to only swim at beaches with a lifeguard, and use extreme caution as ocean water is cold and currents are strong.
The heat wave is caused by a ridge of high pressure, heavy air that's sinking toward the ground. It will take the shape of a heat dome strengthening over the region, the FOX Forecast Center said.
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Phoenix, Los Angeles and Las Vegas are all under Extreme Heat Warnings through Sunday.
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Las Vegas could see 100 degrees on Friday. This would make Sin City's first 100-degree day in March and would shatter its previous March temperature record of 93 degrees.
If downtown Los Angeles reaches 100 degrees, it'll break a temperature record of 99 degrees set in 1879.
The Los Angeles County Office of Emergency Management also reminded people to use caution in the extreme heat, sharing heat safety tips and resources for locals.
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Low snowpack across the mountains in California and Nevada has already led to ski seasons ending early, and now the excess heat is likely to melt a lot more of the remaining snow.
Because the western U.S. relies on snowpack as a "natural reservoir" that slowly releases water through July, this premature spike in temperature is essentially draining the region's water bank account months too early, the FOX Forecast Center said.
As the snow disappears a month early, high-elevation vegetation will begin drying out much sooner, extending the 2026 wildfire season by four to six weeks.
Temperatures across the West are expected to remain slightly higher than usual through at least early April, according to the National Weather Service Climate Prediction Center's temperature outlook.
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