Western U.S. Heat Wave: First 100-Degree Day of 2026 on Deck

A May heat wave is building across the western U.S., bringing the first 100-degree readings of 2026 to the Desert Southwest and parts of California. Records could fall in spots, while coastal cities stay cooler thanks to a Pacific marine layer. Here is the city-by-city forecast.

A May Heat Wave Builds Across the West

It is setting up to be a toasty weekend for much of the West. The region is no stranger to early-season heat. A March heat wave brought down many daily records this year. The upcoming stretch will not be as historic as that March event, but some records may still fall.

March's heat sent temperatures 20 to 40 degrees above the historical average across California and the West. The upcoming warmth is forecast to run 10 to 20 degrees above normal, which is still notable for early May.

The week started cooler in California and the interior West thanks to a storm that brought rain, thunderstorms, and mountain snow. That system is now moving east, allowing dry, hot air to take over.