Cool weather will persist in Riverside County Friday, but the mercury will rise quickly over the weekend and result in unseasonably hot temperatures on Sunday and Monday, according to the National Weather Service.
A weak trough of low pressure is passing through Southern California Friday morning, then another trough of low pressure coming from Northern California will keep temperatures cool through Saturday, forecasters said.
Gusty conditions are expected in the mountains and deserts Friday and Saturday morning, with wind gusts potentially reaching 40-45 mph, according to the NWS.
After that system passes on Saturday, it will be replaced by a subtropical ridge of high pressure, forecasters said. That ridge will bring warm and dry conditions along with periods of weak Santa Ana winds from Sunday through Tuesday.
Winds out of the east and northeast on Sunday are expected to peak around 35 mph and relative humidity will fall to around 15% on Monday, forecasters said.
Highs on Sunday are expected to reach the high-70s to low-80s in the Riverside metropolitan area and the San Gorgonio Pass near Banning, while the mercury in the Coachella Valley will top out at 81.
High temperatures Friday are forecast to reach 78 in the Coachella Valley, 74 in the San Gorgonio Pass near Banning, 69 in Hemet, 70 in Riverside, 67 in Temecula and 53 in Idyllwild.