The National Weather Service has issued a red flag warning for San Diego County's mountains and deserts Friday through Saturday evening.
That means low humidity and strong winds can lead to extreme fire behavior in the Anza Borrego Desert State Park, the San Gorgonio pass near Banning and the Palomar and Descanso Ranger districts of the Cleveland National Forest, according to the agency.
The rest of the county, from the coast to the valleys, could expect temperatures in the 70s through the Labor Day weekend.
"It's going to be a nice, cool weekend for early September," said Larissa Johnson, meteorological technician at the National Weather Service San Diego.