Hot conditions will continue Monday inland San Diego County, with gradually lower temperatures into next weekend, forecasters said.
Record highs were reported throughout San Diego County on Sunday.
It was 92 in Idyllwild, breaking the record for the day of 89 set in 1964. It was 91 in Lake Cuyamaca, breaking the record for the day of 89 set in 1964. It was 105 in Campo, breaking the record for the day of 98 set in 1980. It was 91 in Palomar Mountain, breaking the record for the day of 90 set in 1965.
An excessive heat warning is in effect until at least 8 p.m. Monday, including in county valleys, El Cajon, Poway, San Marcos, Santee, La Mesa and Escondido, with dangerously hot conditions and temperatures from 90 to 100 degrees expected, according to the National Weather Service.
The western valley areas could see highs in the upper 80s, while slightly warmer conditions near the foothills are expected, with temperatures possibly hitting the triple digits.
Coastal San Diego will see partly cloudy conditions and patchy fog in the mornings this week, with mild gusts and highs in the mid-70s.
Downtown San Diego had a high near 78 Sunday, with mostly sunny conditions. Patchy fog is expected after 11 p.m., with a low around 64.
Monday's San Diego surf forecast includes a moderate-risk rip current, with surf height from 2 to 4 feet and mixed south swell from 210 degrees and west swell from 290 degrees.
Fog with visibility from 1 to 3 nautical miles along the near-shore waters is expected to persist Sunday night into late Monday morning. Otherwise, no hazardous marine conditions are expected through Thursday.
"On Tuesday, the marine layer deepens significantly and spreads cooler marine air farther inland, beginning a trend of gradually lower temperatures for all areas," the NWS said.
