The West Coast is bracing for extreme heat with temperatures in desert towns expected to soar as high as 120 Fahrenheit (49 Celsius) and Phoenix likely to extend its streak of 100 days over 100 degrees, forecasters said today.

The southwestern U.S. can expect multiple days of supercharged heat beginning today, with the homeless, elderly, children, and people with health issues at the highest risk for heat illness, the U.S. National Weather Service said.

The worst is likely to dissipate by the weekend but in the meantime much of California can expect sizzling temperatures, even on the Pacific coast which typically gets cooled by an ocean breeze, said Rich Bann, a meteorologist with the weather service’s Weather Prediction Center.

Washington and Oregon are also in line to get baked, Bann said.

“We’re expecting multiple days with widespread high temperatures into the triple digits,” Bann said.

A high-pressure ridge is forming, depriving the region of clouds, cooling winds, showers or thunderstorms that might otherwise offset the intense solar radiation, Bann said.

“When you’re looking at the desert southwest, which is an arid place anyway, all indirect sunlight is going to go into heating the ground,” Bann said.

In Arizona, Phoenix today recorded its 100th straight day at or above 100 F.

“The streak is expected to continue, with no end currently in sight,” the weather service said on X.

The previous record streak was 76 straight days in 1993, the weather service said.