2nd 'Dangerously Hot' Heat Wave Heading For Pass Area, RivCo

UPDATE AS OF 3:05 P.M. FRIDAY: Heat Wave Warning Elevated Across Much Of Riverside County

RIVERSIDE COUNTY, CA — Another heat wave is expected to bear down on Riverside County starting Sunday, with forecasters warning of "dangerously hot" conditions — again.

An excessive heat watch takes effect Sunday morning and will last through Monday evening across the county, the National Weather Service announced.

The "dangerously hot conditions" will bring "extreme heat" that significantly increases the potential for heat-related illnesses, particularly for those working or participating in outdoor activities, the NWS said. "A heat advisory may be issued instead of a warning if these currently forecast temperatures are realized."

Temperatures in the San Bernardino and Riverside County valleys are expected to reach 103, while the Coachella Valley is forecast to see the mercury hit 113 degrees. Mountain communities and the Pass Area can expect daytime highs of 100 degrees, the NWS said.

Monsoon moisture is expected to gradually increase next week, bringing chances for afternoon thunderstorms in the mountains and deserts Tuesday through at least Thursday, according to forecasters.

The unusual June weather comes as the county is recovering from a heat wave that finally broke Wednesday night.