An early-season heat wave in the West this week ended many all-time records in California and Arizona on Wednesday and Thursday.
Summer-like conditions are expected to continue and increase in the east in the coming days.
Across Southern California and the Desert Southwest, nearly 38 million people are under heat warnings. High temperatures in the upper 90s and triple digits were common across the region, thanks to the scattered heat lingering in the West.
On Thursday, Palm Springs, California, reached 107 degrees Fahrenheit, setting a new all-time record for the month of March. The previous record, 105, was set on Wednesday.
The Coachella Valley city of Indio also set a record for March on Thursday, when temperatures soared to 108 degrees.
Several daily records were broken across California, too, including a 101-degree reading in Riverside on Thursday. Records set the previous day included highs of 95 degrees in Anaheim, 88 degrees in Sacramento and 85 degrees in both San Francisco and San Diego, according to the NWS.
In Arizona’s Yuma County, the community of Martinez Lake dropped 110 degrees on Thursday, setting a new record for the highest March temperature in recorded US history, according to the National Weather Service.
Phoenix, meanwhile, recorded its first triple-digit day on Wednesday, with a high of 102 degrees. Temperatures reached 104 degrees there on Thursday.
“This is not only the first 100 ° day of 2026, but it is also the first 100 ° in Phoenix (the last time it happened on March 26, 1988),” the local office of the National Weather Service wrote on Wednesday in X.
Phoenix is expected to reach 106 degrees on Friday and Saturday. An extreme heat warning is in effect for the region until Sunday.
Las Vegas has the same sizzle. On Thursday, the city set a new March record high of 95 degrees, according to the local office of the National Weather Service. Temperatures there could reach 100 degrees on Friday.
Even parts of Oregon, Idaho and Wyoming are experiencing unseasonably warm conditions. The National Weather Service office in Boise said Wednesday afternoon the city averaged 80 degrees.
“This is the first 80-degree day in records dating back to 1875, and only the second time Boise has reached 80 in the winter, the other time being March 19, 1997,” the NWS office said in X.
The heat will continue into the weekend and is expected to move eastward into the Rockies and the central and southern Plains.
“On Saturday, expect high temperatures in the mid to upper 90s across Texas and low to mid 90s as far north as Nebraska and South Dakota,” the NWS said Thursday.
Colorado could set new heat records, too, with Friday forecasts showing highs of 84 degrees in Denver, 86 degrees in Fort Collins and 83 degrees in Boulder. On Saturday, the maximum suggested values increased significantly. The National Weather Service has warned that high temperatures, combined with strong winds and low humidity, are increasing the risk of wildfires in the state.
This week’s heat is caused by a high pressure system that has sealed off the hot air in the West like a lid on a pot.
Although it may be challenging to tease out the direct influence of climate change on certain weather events, global warming is known to make heat waves more frequent, more intense and longer lasting.
