Temperatures are on the rise in Riverside County and are forecast to reach triple digits in the Riverside metropolitan area over the holiday weekend.
High pressure to the south and east of southern California will cause highs to rise gradually through Sunday, when temperatures are expected to be around five degrees above average, according to the National Weather Service.
High temperatures Thursday will be 102 in the Coachella Valley, 91 in the San Gorgonio Pass near Banning, 89 in Hemet, 87 in Riverside, 86 in Lake Elsinore, 82 in Temecula and 79 in Idyllwild.
Highs in the Riverside metropolitan area are forecast to reach 97 on the Fourth of July and 101 on Sunday, while the mercury in the Coachella Valley is expected to reach 108 on the Fourth and 111 on Sunday.
A trough of low pressure will then move inland over central California and bring a cooling trend from Monday through Wednesday, forecasters said.