The fair and warm weather the county has experienced all week will continue through the weekend, the National Weather Service said. A cooling trend is expected by the middle of next week.
The dense fog that prompted an advisory Wednesday morning along the coast will continue today, but may lift by Saturday, said forecaster Dan Atkin. The fog will give way to clear and sunny skies along the coast.
Skies along the beach will be hazy after the morning low clouds burn off, Atkin said. Conditions inland and in local mountains and deserts, will be clear.
The high at Lindbergh Field Thursday was 81, well short of the record for an Oct. 8, 93 degrees in 1899.
Air quality around the county Thursday was moderately unhealthy except in downtown San Diego, where the air quality was good, the county Air Pollution Control District reported. Today's air quality is expected to be the same.
The eastern end of a large high-pressure system has settled over Southern California, creating the warm weather, Atkin said.
Beach highs today through Sunday will be in the low 70s. The ocean water is 67. The surf is 2-4 feet.
Highs along the coast will be from the upper 70s to the mid-80s today through Sunday, Atkin said, with overnight lows of 50 to 60.
Inland, the highs will range in the low-to mid-90s, he said, and lows will be in the low-to mid-50s.
Mountain highs today through Sunday are expected to be in the mid-70s to low 80s. Overnight lows will range from 45 to 55, Atkin said.
Daytime highs in the desert are expected to stay in the 90s, and lows are expected to be in the mid-50s to mid-60s.