The most prolific March heat wave in at least 14 years has already smashed monthly records in over 170 cities from the Southwest to the Plains and East, and will have staying power in the Southwest and Plains in its second week.
(MAP: Temperatures Right Now)
First, let’s recap the incredible records we’ve seen shattered so far. Then we’ll look and see how long this heat will last.
New US March Heat Record
Before this heat wave, the hottest March temperature on record anywhere in the U.S. had been 108 degrees in Rio Grande City, Texas, on March 30, 1954, and on March 14, 1902.
But at least one location in the U.S. tied or exceeded that March national record four days in a row from March 18 through 21.
This hit its peak on March 20, when four reporting stations in the lower deserts of southeast California and southwest Arizona hit 112 degrees, shown in the map below. You can’t make it up that one of these stations was near the town of Winterhaven.
These highs were only one degree shy of tying the April U.S. record high set at Death Valley, California, according to weather historian Christopher Burt. And that happened in late April — April 22, 2012 and April 24, 1946.
March Statewide Records
It also appears that the hottest March temperatures on record for at least a dozen states have been either tied or broken.
We touched on the California and Arizona records above (112 degrees) as national records, but among some other state records that appear to have been tied or set include:
Nevada: 106 degrees on March 20 and 21
Colorado: 96 degrees on March 21
Nebraska: 99 degrees on March 21
Missouri: 97 degrees on March 21
Minnesota: 88 degrees on March 21
The other states are shown on the map below.
For bigger state or national records like these, an ad hoc committee of meteorologists and climatologists is usually convened to examine the data and the reporting station before it becomes a new, official record.
march record heat wave
City March Records
So far, over 170 locations with data since the 1960s or earlier have tied or set new March records from California to Pennsylvania during this heat wave.
Some of those records are shown in the map below from NOAA’s Weather Prediction Center.
Phoenix only had one March day of triple digit heat on record prior to this heat wave. They hit the 100s five days in a row from March 18-22, topping out at 105 degrees on March 20 and 21. Incredibly, that’s equal to their April monthly record, which was set almost a month later in the calendar on three dates ranging from April 20-29 in three past years.
Other major cities that tied or set new March records included San Francisco’s first March 90-degree high downtown, Las Vegas (four straight days in which they tied or topped their previous March record, reaching 97 degrees on their hottest day), Salt Lake City (84 degrees), Boise (83 degrees) and Denver (85 or 86 degrees for three straight days).
It wasn’t just a western heat wave.
March records were tied or set in Lubbock, Texas (98 degrees), Kansas City (93 degrees), Des Moines, Iowa (91 degrees), Nashville, Tennessee (89 degrees), Louisville, Kentucky (89 degrees), Indianapolis, Indiana (88 degrees), Columbus, Ohio (86 degrees), and Pittsburgh (84 degrees).
Perhaps the most extraordinary record heat east of the Rockies happened in Nebraska on March 21.
Both Lincoln and Omaha not only demolished their March record, after reaching 97 degrees in Lincoln and 96 in Omaha, but it also tied their April record.
Many of these over 170 cities tied or topped their previous March records multiple days in a row. Thermal, California, reached or topped their previous March record of 103 degrees a staggering six days in a row from St. Patrick’s Day through the following Sunday.
Several of these cities reached the 80s, 90s, or 100s for the first time in their recorded history.
Last weekend, parts of the Plains, were as much as 45 degrees warmer than average.
Put simply, this is likely the most significant, long-lived March heat wave the nation has experienced since the March 2012 heat wave rewrote the record books in the central U.S. and Canada.
AP Photo/Gregory Bull
There’s Still More Ahead In This Heat Wave
This heat wave is nowhere near over with in the Southwest.
And we expect another pulse of heat to push into parts of the Plains and South this week.
We’re expecting many dozen more daily record highs from California possibly as far east as parts of Georgia and the Carolinas.
And we can’t rule out more March records set in a few areas, though last week’s heat set a much higher bar.
(MORE: Heat Safety And Preparation)
How hot are we talking about?
Triple-digit highs: Parts of the Desert Southwest, including Phoenix, and the lower Colorado River Valley could again see triple digit heat through much of this week. A few of the hottest spots in Texas, possibly southwest Oklahoma, could reach 100 degrees around Thursday.
The 90s: California’s Central Valley, even parts of the Bay Area, will rise into the 90s for multiple days.
(MAPS: 10-Day US Forecast Highs, Lows)
Why So Hot So Soon?
The reason for this heat wave in particular has to do with the ridge of high pressure, also known as a heat dome, that was parked over the West.
This heat dome is record-breaking for March, comparable in strength to ones we see in June. You can see the general position of the high pressure on the satellite loop below in the darker shading.
Jonathan Erdman is a senior meteorologist at weather.com and has been covering national and international weather since 1996. Extreme and bizarre weather are his favorite topics. Reach out to him on Bluesky, X (formerly Twitter) and Facebook.