A massive heat dome is spreading across the U.S., breaking March temperature records in 14 states and threatening to become one of the most expansive heat waves in American history, meteorologists say. The high-pressure system, which has already caused record-high temperatures in the Southwest, is moving eastward, bringing extreme heat to the Southern Plains and Midwest.
Core Facts
- The heat dome has shattered March records in 14 states, with temperatures reaching the 90s Fahrenheit (mid-30s Celsius) in some areas.
- Meteorologists predict the heat wave will persist until mid-April, affecting up to one-third of the continental U.S.
Deeper Dive & Context
Heat Dome Mechanics
The heat dome acts like a lid, trapping hot air over a region. In Flagstaff, Arizona, temperatures are expected to exceed previous March records for 11 or 12 consecutive days. The system’s eastward movement will push temperatures into the 90s across the Southern and Central Plains by Wednesday.
Historical Comparison
Weather historian Chris Burt notes that this heat wave may surpass two other historic events—the 2012 Upper Midwest heat wave and the 2021 Pacific Northwest heat wave—in physical area. However, it is less intense than the 1936 Dust Bowl heat waves, which occurred over two months during summer.
Public Health Impact
While the heat wave is less humid than summer heat, meteorologists warn that it still poses risks, particularly for vulnerable populations. The National Weather Service (NWS) forecasts over 200 new record high temperatures this week, with moderate heat-related impacts expected.
Regional Forecasts
- Southwest: Cities like Phoenix and Palm Springs have already recorded their earliest 100-degree days on record.
- Southern Plains: Northern Texas, eastern New Mexico, and the Oklahoma panhandle are expected to face the most widespread impacts by Thursday.
- Midwest: Denver, Las Vegas, and Salt Lake City are at risk of breaking daily and all-time March temperature records.
Expert Perspectives
- Gregg Gallina (NWS): The heat wave’s expansive area is “bizarre” and unprecedented for March.
- Jeff Masters (Yale Climate Connections): The heat dome’s duration and intensity are unusual for this time of year.
- Bill Deger (AccuWeather): The heat wave follows an earlier surge in the Southwest, where temperatures soared 30 degrees above average.