San Diego's Weather Forecast for Sept. 20, 2021: Warming up to start fall

Posted at 5:08 AM, Sep 20, 2021
and last updated 2021-09-21 00:31:00-04

Santa Ana winds will put a brief pause to our cool weather. Dry, gusty winds, and above normal heat is expected as we enter the fall season on Wednesday.

The autumnal equinox happens at 12:21pm on Wednesday though it will be feeling more like summer with some 80s for the warmer coastal areas and 90s inland.

A Heat Advisory has been issued for inland communities and foothills. The heat will impact most of the county on Tuesday and Wednesday, temperatures will trend about 5 to 10 degrees above normal, with low relative humidity, and elevated fire danger.

The bump in temperatures is due to mild Santa Ana winds through midweek. Expect east and northeasterly winds of 15 to 30mph with peak winds in the foothills and mountains. Humidity will drop between 10 to 20%.

Coastal communities will also see fewer clouds due to the shift in wind direction, weakening the marine layer. The swell is coming from the south and west averaging 1 to 3 feet.

Monsoon moisture returns Thursday bringing with it a chance for showers and thunderstorms to the county, though the best chance will be in the mountains and deserts. A slight chance for storms continues through Saturday.

Temperatures will start trending downward Thursday into the weekend, though humidity will be higher while the monsoon pumps in moisture.

Tuesday's Highs:
Coast: 73-83°
Inland: 90-98°
Mountains: 85-92°
Deserts: 98-102°

Follow ABC 10News Meteorologist Angelica Campos on Facebook & Instagram @Camposcrusher and Twitter @10NewsCampos