A heatwave rolling through Southern California will send temperatures soaring in San Diego County's western valleys, mountains and deserts this weekend.
A strong system of high pressure will start building Friday over Arizona and New Mexico, ushering in sweltering heat in most of Southern California through Monday, forecasters said.
The National Weather Service issued an excessive heat warning that will be in effect from 10 a.m. Saturday through 8 p.m. Monday in the deserts, while a heat advisory will last from 10 a.m. Saturday through 8 p.m. Sunday in the western valleys and the mountains.
NWS officials urged residents to drink plenty of fluids, stay out of the sun and check up on relatives and neighbors. Also, young children, senior and pets should never be left unattended in a vehicle parked during the day, with car interiors able to reach lethal temperatures in minutes.
High temperatures Friday are forecast to reach 78 degrees near the coast, 86 inland, 89 in the western valleys, 98 near the foothills, 98 in the mountains and 110 in the deserts. Sunday's high could reach 120 in some desert communities.
Slight cooling will arrive in the deserts on Tuesday and continue through Thursday, forecasters said.