A thick, persistent marine layer will return to San Diego County this week, resulting in cooler, seasonal weather two weeks before the fall equinox, the official start of autumn, the National Weather Service says.
San Diego’s daytime high temperature is expected to be 74 on Tuesday, 72 on Wednesday, 71 on Thursday and 73 on Friday. The seasonal average is 78.
Forecasters say the marine layer is likely to spread to the inland foothills and valleys, cooling areas like Escondido, where the high is predicted to be 80 on Tuesday, 76 on Wednesday and Thursday, and 79 on Friday.
Sea surface temperatures, which have been in the 70 to 73 degree range in most areas, also will slip.
There are no major storms in the 10-day forecast, denying the region much-needed rain. Since the water year began on Oct. 1, San Diego International Airport has recorded 4.61 inches of precipitation, which is 5.90 inches below average. The water year ends on Sept. 30.
NOAA forecasters say Southern California is likely to be drier than normal this fall due to an emerging La Niña.