The marine layer will thicken along the coast during the first half of this week, keeping temperatures a few degrees below average, says the National Weather Service.
Daytime highs in San Diego will only reach 73 through Thursday. It also will be on the cool side across many inland valleys and foothills. Forecasters say the daytime high will be in the 77- to 80-degree range through Wednesday in Escondido, and only marginally warmer in El Cajon.
But the low pressure is expected to fade during the second half of the week, and temperatures will gradually tick upward going into next weekend. Friday’s high in San Diego is projected to be 78. It could hit 80 on Saturday.
Forecasters say Santa Ana winds may blow late in the week.
The surf will remain small along the entire coastline through Wednesday. Sea surface temperatures are in the 67- to 68-degree range.
There will be a full moon on Thursday, October 5.