An extreme heat warning was expected to remain in effect in Riverside County until late this week as summer-like weather lingers into early fall, forecasters said Sunday.
The heat warning was expected to remain effective until at least 8 p.m. Thursday, with significant cooling likely next weekend, according to the National Weather Service.
Impacted areas included Corona, Riverside, Temecula, Hemet and Moreno Valley due to temperatures in the upper 90s and low triple digits.
Sunday’s temperatures were expected to reach 103 in downtown Riverside, 100 in Temecula, 99 in Hemet, 104 in Coachella and 101 in Palm Springs. Temperatures were expected to remain similar through the beginning of the week.
The warmest days are expected to be Wednesday and Thursday, with highs around 101 in downtown Riverside and Hemet, 99 in Temecula, 106 in Coachella and 105 in Palm Springs both days.
Cooling center locations in Riverside County can be found at countyofriverside.maps.arcgis.com/apps/webappviewer/index.html?id=5ffaf74e67244 b829796eeb8df6bc6a7.
Toward the end of the week, the high pressure ridge will be weakening in response to a trough of low pressure approaching from the northwest, the NWS said.
“The forecast reflects this with a trend toward noticeably lower temperatures beginning next Friday, although high temperatures on Friday will still be as much a 15 degrees above normal in the western portions of the inland valleys,” forecasters added.
By next Saturday, the downtown Riverside and Hemet areas were expected to reach around 88 degrees, Temecula 85, and Coachella and Palm Springs around 97 degrees, according to the NWS.
With extreme heat expected all week over most of Southern California, power providers were urging customers to conserve electricity wherever possible to help avoid outages.
The California Independent System Operator, or Cal-ISO, which manages the state’s power grid, has already issued a “Restricted Maintenance Operations” notice for 10 a.m. to 10 p.m. Monday and Tuesday, urging suppliers “to avoid taking actions which may jeopardize generator and/or transmission availability.”
“We are not forecasting any supply shortfalls at this time, but wanted to prepare consumers in the event that we need to call a Flex Alert,” according to a statement from the agency. “We will continue to monitor forecasted demand and supply conditions and will provide additional updates as necessary.”
A Flex Alert is issued when Cal-ISO believes power demand may exceed supply. The alert is a voluntary call for conservation by residents. If conditions worsen, Cal-ISO could issue additional emergency alerts, potentially leading to rolling blackouts in the most critical power-shortage situations.
And as always during a heat wave, public safety officials reminded people to never leave children or pets inside unattended vehicles for any time at all, as the temperature inside a vehicle can turn deadly in a matter of minutes.