Sunrise on Friday from Volcan Mountain in East County
Sunrise on Friday from Volcan Moutain in East County. Image from UCSD HPWREN network

A heat wave is expected to send temperatures soaring well into the triple digits in the San Diego County deserts through the weekend.

The National Weather Service office in San Diego issued an excessive heat warning for the deserts that will be in effect from 10 a.m. Friday through 8 p.m. Monday.

High temperatures near the coast will be in the high 70s to low 80s Friday, while temperatures are expected to reach the high 80s Friday in the western valleys, forecasters said.

A high of around 113 degrees is expected Friday in Borrego Springs.

The scorching temperatures could cool a degree or two over the weekend, but high temperatures were expected to remain around the same before cooler weather arrives Tuesday, according to the weather service.

The weather service advised that those who work outdoors should avoid the midday sun, wear light, loose-fitting clothing and drink plenty of water.

Nighttime lows will be in the mid to high 80s Friday in the county deserts, posing e a health risk to those who don’t have access to air conditioning because the body needs time to cool down from the day’s heat.

— City News Service

Chris Jennewein is founder and senior editor of Times of San Diego.