A brutal heat dome has settled over the American West, turning late winter into a full-blown summer emergency.
Temperatures across California, Nevada, Arizona, and beyond have smashed records that stood for over a century, and meteorologists warn the worst is not over yet.
WHAT IS A HEAT DOME?
A heat dome is a stubborn area of high pressure in the atmosphere that traps warm air close to the ground, much like a lid on a boiling pot. As a result, clouds cannot form, rain stays away, and temperatures simply keep climbing.
The dome has been parked over Southwest America since last week and is expected to linger well into the weekend.
As the high pressure strengthens, it blocks weather systems from entering the region entirely, causing what meteorologists describe as a traffic jam in the sky.
WHY IS IT SO HOT IN CALIFORNIA AND NEARBY STATES RIGHT NOW?
Phoenix in Arizona hit 101 degrees Fahrenheit on Wednesday, setting a record for the city’s hottest day in March and also the earliest point in the year the place reached 100 degrees Fahrenheit.
Palm Springs in California hit 105. Nevada’s Las Vegas, at 94, also set a record for March. Peak temperatures are forecast for Friday, with Palm Springs expected to top 108 and Phoenix 106.
Downtown Los Angeles in California hit 90 degrees Fahrenheit on Monday, 98 on Tuesday, and was forecast to stay in the 90s through at least Saturday. The city typically does not see its first 90-degree day until early May.
California’s San Francisco, usually kept cool by the surrounding bay waters, recorded temperatures in the 80s across the week, which is highly unusual for a city that averages only 17 such days in an entire year.
COULD THIS HEAT BREAK APRIL RECORDS TOO?
Not only will temperatures break March monthly records, but this heat wave is also expected to break April records. Around 800 high-temperature records are forecast to be neared, tied, or broken at 165 locations in western and central states, some by more than 10 degrees Fahrenheit.
A forecast high of 114 degrees Fahrenheit in Riverside County, California, on Friday could shatter both the March and April national temperature records.
DOES CLIMATE CHANGE HAVE A ROLE IN THIS?
Climate change is pushing up average temperatures and increasing the likelihood, severity, and frequency of high-temperature extremes.
Even though heat domes are not a new phenomenon, one occurring in 2026 can bring far more extreme temperatures than one in 1996 or 1966 because of the steepening background warming trend.
Researchers who studied a similar heat dome that struck the Pacific Northwest in June 2021 found that while such events are not becoming more frequent, they are undeniably becoming more dangerous.
Some relief is expected over the weekend, with more widespread cooling arriving by Monday and Tuesday across southern California and southern Arizona.
