Late Summer Heat Wave Bears Down on San Diego County Through Saturday

A late summer heat wave is bringing sizzling temperatures to the San Diego area this week, sending thermometer readings into triple digits in some locales, forecasters said.

Thursday and Friday will be the peak of the heat with high temperatures 15 degrees or higher above average in parts of the valleys, according to the National Weather Service.

The hot spell prompted the weather agency to issue excessive heat warnings for the inland valleys, mountains and deserts of the county, effective through 8 p.m. Saturday.

Over the period, daytime highs are expected to reach 102 to 107 degrees in communities such as El Cajon, Escondido, La Mesa, Poway, San Marcos and Santee; the 90s to 104 in Julian, Pine Valley and other highland spots; and 112 to 118 in the arid, sun-baked eastern reaches of the region.

Things will be somewhat less stifling along the coast, where an NWS heat advisory warning of 85- to 95-degree temperatures will be in effect from 11 a.m. Thursday to 8 p.m. Friday.

Authorities advise people to protect themselves from potential heat-related ill health effects by drinking plenty of non-alcoholic fluids, staying out of the sun during the hottest times of the day, taking shelter in air conditioned spaces if possible and checking up on at-risk relatives and neighbors.

A return of monsoonal moisture over the weekend will bring some cooling to the deserts and a slight chance of afternoon showers and thunderstorms in the mountains and deserts, NWS said.

Drier weather will return early next week with slight cooling, according to meteorologists. The marine layer will become shallower with night and morning low clouds becoming patchier and limited mostly to the immediate coast.

City News Service contributed to this article.