An exceptional heat wave is hitting the southwestern United States, with record temperatures expected to reach up to 41.6°C in California, Arizona, and Nevada.

While winter is not yet officially over, an unusual heat wave for the season is hitting parts of the southwestern United States, with temperatures far above normal.

In several areas of Southern California, Arizona, and Nevada, the National Weather Service (NWS) has issued extreme heat warnings. In Las Vegas, Southern Nevada, the mercury already reached 35°C on Thursday, with temperatures expected to climb through the weekend, potentially reaching 41.6°C, well above usual March highs.

The first major heat wave

“We are experiencing temperatures well above normal,” said Rose Schoenfeld, a meteorologist with the NWS. She also noted that this is “the first major heat wave this year… coming after periods of cooler temperatures,” emphasizing that local populations are not yet acclimatized to these conditions.

Faced with this event, deemed "extremely rare for the month of March," the NWS recommends staying in air-conditioned spaces and drinking plenty of fluids. The phenomenon is also spreading to northern Mexico, which is also experiencing this unusual rise in temperatures.

A series of extreme events in 2025

According to scientists, this type of event is part of a broader trend linked to climate change. The year 2025 was marked by a succession of extreme events (heat waves, storms, cyclones and fires) whose frequency and intensity are increasing globally.

"We will probably continue to break daily records, as well as historical records in some areas," warns Rose Schoenfeld, as these early temperatures could also disrupt ecosystems, on the eve of the arrival of spring in the northern hemisphere on March 20.