Cold, frosty weather in parts of San Diego County early Thursday morning is expected to give way to somewhat warmer conditions later in the day.
Overnight low temperatures fell to 21 degrees on Mount Laguna, 23 on Palomar Mountain, 25 in Julian, 29 in Ramona, 32 in Alpine, 34 in Escondido and Borrego Springs, 35 in Oceanside, 37 at Miramar and 44 in San Diego, according to the National Weather Service.
A frost advisory for the inland valleys will expire at 8 a.m. Thursday. Forecasters urged residents to cover sensitive outdoor vegetation and bring pets inside.
"Temperatures will remain in the upper 20s to mid 30s past sunrise with areas of frost in colder wind-sheltered locations in the inland valleys and the southern Coachella Valley," according to the weather service.
Temperatures across San Diego County are expected to be warmer Thursday, but still slightly below average, forecasters said. Above or around average temperatures are in Friday's forecast.
High temperatures along the coast are expected to be around 64 degrees Thursday and in the 67 to 71-degree range Saturday, according to the weather service. In the valleys, forecast high temperatures of 62 to 67 degrees for Thursday are expected to jump to 69 to 74 degrees on Friday.
In the mountains, an even more prominent warmup is expected. Highs of 52 to 60 degrees will increase to 60 to 69 Friday.
High temperatures in the deserts are expected to rise a few degrees as well. Temperatures of 58 to 63 degrees Thursday are expected to inch up to 64 to 69 degrees.
