
The temperature is likely to hit 110 degrees Thursday and Friday in Borrego Springs, a level the desert town hasn’t reached since Sept. 9, 2023, the National Weather Service said.
Ocotillo Wells also could top out at 110 degrees, due to a high pressure system out of the Great Basin.
But San Diego County’s coastal cities will be about 40 degrees cooler as a countervailing low pressure system at sea continues to produce a strong marine layer at local beaches.
“It’s not unusual to have such large differences in temperatures this time of year,” said Greg Martin, a weather service forecaster. “The ocean is still cold, and the deserts can heat up a lot because the seasonal monsoon has yet to appear. The monsoon carries moisture that can hold down the heat.”
The long-term forecast suggests that the gloomy weather along the coast will last at least until June 12, when then San Diego County Fair opens in Del Mar.