Summer weather is headed for Southern California this weekend. How long will it last?

A person relaxes in grass near trees in pink bloom
A person relaxes in the grass near trees in bloom in Aldrich Park at UC Irvine as temperatures rise into the weekend.
(Allen J. Schaben / Los Angeles Times)

Put away your sweater and break out your sunscreen.

Warmer than normal temperatures are headed to Southern California this weekend.

An onshore flow could weaken Friday and Saturday, ushering in temperatures that will rise by 5 to 10 degrees for most areas away from the coast, according to the National Weather Service. The beaches are expected to have temperatures in the upper 60s while the valleys are likely to be in the lower 90s.

The warming trend comes only a couple of months after Southern Californians endured one of the drabbest and wettest winter in recent memory.

On Saturday, temperatures will be 1 to 3 degrees above normal along the coasts to the mid-60s and 5 to 10 degrees above normal inland, to the mid-80s, according to forecasters. Then on Sunday, the increase of onshore flow will cool most areas by 4 to 8 degrees.


But the cooling trend will be short-lived. Temperatures are expected to jump again 4 to 8 degrees in areas away from the beaches Monday and climb by a degree or two by Tuesday, according to the weather service. Maximum temperatures will be 5 to 10 degrees above normal each day, with some areas seeing temperatures as high as 12 degrees higher than normal.

A weakening high-pressure system should cool down the region Wednesday and Thursday, but temperatures will still be above normal. There’s a slight chance for showers and thunderstorms, similar to a monsoonal pattern, over the eastern San Gabriel Mountains, meteorologists says.

A heat advisory has been issued for the San Joaquin Valley, which could see temperatures of 94 to 99 degrees Saturday afternoon through Monday night, according to the weather service.

Health officials advise that people drink plenty of water during these warm spells, stay in an air-conditioned room indoors, stay out of the sun and prevent young children and pets from being left in unattended cars.