Temperatures are expected to fall to their lowest readings of the season overnight Monday in San Diego County, forecasters said.
"This is going to be for the whole county, but especially the valleys and deserts," NBC 7's meteorologist Francella Perez said. "Even some frost will be a possibility."
Monday will be dry and sunny, but the highest temperatures of the day will remain on the colder side.
Get top local stories in San Diego delivered to you every morning. Sign up for NBC San Diego's News Headlines newsletter.
Gale warning
A gale warning will be in effect until 3 a.m. Monday for coastal waters from San Mateo Point to the Mexican Border out to 30 nautical miles, extending 30 to 60 nautical miles out to San Clemente Island, with ocean- surface winds up to 30 knots and gusts up to 40 knots.
High-surf advisory in San Diego County
The high-surf advisory will be in effect until 6 a.m. Monday and includes warnings of dangerous swimming and surfing conditions and beach erosion.
Monday's San Diego surf forecast includes a high-risk rip current, with surf height from 3 to 6 feet, with sets to 7 feet in the morning and a west swell from 290 degrees, according to the National Weather Service.
Another round of king tides are expected to hit San Diego beaches on Jan. 11-12.
Temperatures
Along the coast, a mix of partly cloudy and sunny conditions is expected for this week, with daytime temperatures hitting the lower 60s. Inland valley areas are expected to be partly cloudy through Friday, with highs reaching the high 50s to low 60s.
The desert areas are expected to see highs in the lower 60s throughout the week, with daytime temperatures ranging from the mid-40s to mid-50s in the mountains.
Downtown San Diego is expected to be partly sunny Monday and Tuesday, with highs in the low 60s.