This week, much of the western United States is experiencing a summer-like heatwave in March, with temperatures soaring across California and the Southwest, raising significant climate concerns.

Forecasters predict high temperatures exceeding 90 degrees Fahrenheit will blanket Southern California and reach triple digits in parts of Arizona and Nevada. On Monday, about 39 million residents were placed under heat warnings, with expectations for the heatwave to intensify as the week progresses.

The National Weather Service attributes this “unusually rapid” heatwave to a unique atmospheric pattern characterized by a dome of high pressure settling over the West, trapping heat and humidity.

“We anticipate daily record ties and new records emerging throughout Southern California, the desert Southwest, and the Great Basin over the next few days,” the agency noted in their Monday short-term forecast. “These rising temperatures are paving the way for even more extreme and widespread record heat later this week.”

In Los Angeles, temperatures are expected to reach the mid to upper 90s this week, peaking at 98 degrees on Thursday. In Phoenix, readings could soar to 105 degrees by Thursday, while southern Nevada cities might hit 107 degrees, marking an exceptionally hot start to the year.

“Temperatures will be more than 20 degrees above normal, making it feel more like early June than mid-March,” the Las Vegas Weather Bureau stated in a recent post on X.

Cities likely to break monthly temperature records in the coming days include San Francisco, Los Angeles, Sacramento, and Palm Springs in California, alongside Phoenix and Tucson in Arizona, Las Vegas, Salt Lake City, Albuquerque, Colorado Springs, and Denver in Colorado.

Heat domes occur when a powerful, persistent area of high pressure hovers over land, effectively trapping hot air.

This week’s heatwave is especially concerning due to its unusual timing and extended duration. The Bureau of Meteorology cautioned that this heat dome might be “one of the strongest we’ve observed for this time of year,” with little relief expected until late next week.

While linking specific extreme weather events directly to climate change remains challenging, studies indicate that heatwaves are becoming more frequent, intense, and prolonged as global temperatures rise.

Extended periods of extreme heat pose significant risks to vulnerable populations, including children, the elderly, and individuals with pre-existing health conditions, especially as they adjust to summer-like climates.

The National Weather Service San Diego office warned, “Moderate to severe heat risk is expected. Please stay safe, especially for those without air conditioning. Avoid outdoor activities during peak heating hours.” They shared this announcement via X on Sunday.

This March heatwave has further worsened the West’s ongoing snow drought, diminishing the region’s already low snowpack and increasing concerns about wildfire risks and water availability for the upcoming months.

As the West faces soaring temperatures, a major winter storm is impacting the upper Midwest and Upper Great Lakes, with heavy snowfall anticipated in Wisconsin and Michigan on Monday. More than 120 million residents from the Mississippi Valley to New England also face wind warnings, with potential for damaging winds and tornadoes in areas like Pennsylvania, New Jersey, and Washington, D.C.

Simultaneously, Hawaii has been battered by a powerful atmospheric river, bringing continuous rain and resulting in widespread flash flooding and landslides over the past five days.