A heat wave that swept through parts of Riverside County earlier this week is expected to flare up Thursday, sending temperatures into triple digits before cooling for the weekend.
The heat prompted the National Weather Service to issue a heat advisory in effect until 8 p.m. in Riverside County Valleys.
The return of monsoonal moisture to the region has brought a chance of scattered thunderstorms through Friday in the county mountains and deserts, including the Coachella Valley and San Gorgonio Pass near Banning, forecasters said.
High temperatures Thursday were expected to reach 107 degrees in Thermal, 107 in Palm Springs, 99 in Riverside, 99 in Temecula and 104 in Indio, forecasters said.
The weather service and law enforcement caution that those who work outdoors should avoid the midday sun, wear light, loose-fitting clothing and drink plenty of water.
Avoid leaving senior citizens and kids at home without air conditioning, if possible. And never leave a child, senior or pet in a parked vehicle, even with windows cracked open, because interior temperatures can quickly turn lethal.
Monsoonal moisture is expected to decrease and temperatures are expected to drop to slightly above seasonal norms for the weekend, forecasters said.