A significant heat dome has settled over the Southwest, shattering March temperature records across 14 states in the U.S. It appears to be on its way east, potentially evolving into one of the most extensive heat waves in U.S. history, as noted by meteorologists and weather historians.
This intense heat isn’t expected to ease up anytime soon—likely hanging around until the middle of next week, coinciding with the start of April, according to Greg Gallina from the National Weather Service’s Weather Prediction Center.
“Essentially, the entire country is set to experience rising temperatures,” Gallina remarked. “The range of record temperatures is remarkably broad, which is quite unusual.”
Jeff Masters from Yale Climate Connections explained that this heat dome acts like a lid on a pot, trapping hot air in the area. In Flagstaff, Arizona, for instance, temperatures could exceed March’s record for 11 to 12 days straight.
Gallina mentioned that as the dome shifts eastward, temperatures in the southern and central Plains are expected to rise into the 90s Fahrenheit (mid 30s Celsius) by Wednesday. He estimated that roughly a quarter to a third of the contiguous U.S. will break their March temperature records.
Climate historian Chris Burt indicated that while this heat wave is extensive, it might be smaller than other significant heat events from the past, such as the one that affected the Upper Midwest and Northeast in 2012, or the Pacific Northwest in 2021.
Though this heat wave may not measure up to the notorious 1936 Dust Bowl heat wave, which spanned two months, it still poses serious concerns. Burt pointed out that the intensity of both the Dust Bowl and the 2021 event was higher, partly due to the cooler conditions experienced in subsequent months.
However, there’s a silver lining—this current heat wave won’t be accompanied by high humidity, which often exacerbates discomfort during hotter spells.
On Friday, temperatures reached 112 degrees Fahrenheit (44.4 degrees Celsius) in parts of Arizona and California, marking the hottest day ever recorded in March in the continental U.S., surpassing the previous record by 4 degrees (2 degrees Celsius), just a degree shy of the all-time hottest day in April.
Maximiliano Herrera, a climatologist who monitors global weather patterns, identified 14 states that registered their warmest March days since the arrival of the heat dome, including California, Arizona, and Nevada, among others.
In Mexico, even records from May were broken, with March soaring higher by 14 degrees Fahrenheit, which is notably more extreme than records from previous years.
The National Center for Environmental Information reported that at least 479 weather stations recorded historical March temperatures between Wednesday and Saturday. Herrera suggested that the real number of broken records might be significantly larger, citing over 1,472 daily records that were also surpassed.
An issue compounding the situation is the jet stream, which usually shifts weather systems from west to east, seems to be primarily stuck in the west. Meanwhile, Hawaii is dealing with a storm, resulting in heavy rains and flooding.
Recently, some international climate scientists concluded that such record-breaking temperatures in Western North America are “virtually impossible” without the influence of climate change, emphasizing the impact of fossil fuel combustion.
The findings show that human activity has increased temperatures by at least 4.7 degrees Fahrenheit (2.6 degrees Celsius). According to Masters, the heat dome should start to dissipate by late next week, although patience will be needed for relief to arrive.
