A heat dome will send temperatures into the triple digits across the West—with summer still 2 weeks away

(Credit: Robert Gauthier—Los Angeles Times/Getty Images)

The official start of summer is still 16 days away, but Western states are already bracing for triple-digit temperatures as the first substantial heat wave of the year moves into California and Arizona.

A heat dome moving up from Mexico is expected to bring record-high temperatures to much of the West Coast, with California taking the brunt of the heat. Temperatures in some deserts could reach as high as 120 degrees.