Make some lemonade. San Diego’s heat wave will last through Wednesday

The California Independent System Operator has issued a statewide Flex Alert due to the heat wave.
The California Independent System Operator has issued a statewide Flex Alert due to the heat wave.

Humid air could bring thunderstorms to the mountain over the weekend


Make some lemonade. This heat wave that baked San Diego County Friday is going to last a while.

The National Weather Service says daytime highs at local beaches will be in the upper 70s and low 80s through next Wednesday. Areas a bit inland will hit the upper 80s. And everything east of Interstate 15 will be in the 90s and low 100s.

“This is going to go on for days,” said Alex Tardy, a weather service forecaster. “You can expect readings of 100 or more in places like Escondido, Santee and Lakeside.

“We also could get thunderstorms in the mountains as early as Saturday as the humid air starts to come in.”

Friday was hot enough to prompt the California Independent System Operator (ISO) to issue a statewide Flex Alert that calls for voluntary electricity conservation.

Cal-ISO is trying to protect the state’s power grid, which will come under increased demand, mostly from residential air conditioning use.

The “southwest U.S. will be experiencing near-record or record-breaking heat, up to 10 to 20 degrees above normal in some areas,” Cal-ISO said in a statement.

Through 3:15 p.m. Friday, southeastern Escondido had hit 104, El Cajon, Alpine and Gillespie Field had reached 100, and Rancho San Diego topped out at 98. San Diego International Airport reached 86, which is 10 degrees above average.

The excessive heat warning warning issued by the weather service will remain in effect for all areas except the immediate coast through 9 p.m. on Monday.

A coastal eddy could ease the heat at area beaches on Sunday. But the marine layer will be very shallow and San Diego could still top 80 degrees.

Nights won’t be made for sleeping. The overnight lows will be in the 70s, about 10 degrees above average.