Thursday was the official first day of summer, and this weekend it’s going to feel like it across Southern California.

“A heat wave is on the rise, starting today,” said KTLA’s Gene Kang. “Some areas will be in the triple digits.”

According to the National Weather Service, Saturday’s widespread highs in parts of inland Southern California range from 96 to 106 degrees. Near the coast, temperatures in the high 70s to mid 80s should be expected.

NWS heat wave
A graphic from the National Weather Service shows the incoming high temperatures in parts of Los Angeles and Ventura Counties. (National Weather Service)

Temperatures clearing 100 degrees are expected in the San Gabriel and San Fernando Valleys on Saturday and Sunday.

The NWS issued a heat advisory for Southern California that begins 10 a.m. Saturday and lasts until 8 p.m. Sunday. The advisory warns residents that the high temperatures could cause heat-related illness if precautions aren’t taken.

Even after the weekend, the heat wave is expected to persist for several days with temperatures in the high 80s and low to mid 90s in parts of Los Angeles, Orange, San Bernardino and Riverside Counties.

Those precautions include drinking plenty of fluids, staying in air-conditioned structures and staying out of the sun as much as possible.

“Seven days of heat headed our way,” said KTLA’s Henry DiCarlo. “Stay hydrated and take care of your pets. Make sure they’re safe and inside as well.”