Murrieta temperatures will climb past 100°F starting Friday, Oct. 2, and stay dangerously high through at least Wednesday, Oct. 7, according to the National Weather Service.
The NWS San Diego office issued an Extreme Heat Watch at 3:05 a.m. Wednesday, Sept. 30, covering Riverside and San Bernardino county valleys. The watch takes effect at 10 a.m. Friday, Oct. 2, and runs through 9 p.m. Wednesday, Oct. 7.
A high-pressure ridge moving in from the Great Basin of Nevada and Utah will begin dominating weather patterns by Thursday, Oct. 1, according to a Patch report citing the NWS. Low-pressure troughs linked to Tropical Storm Odalys and Hurricane Polo near the Baja California peninsula have kept Inland Empire temperatures down through Wednesday.
Murrieta's day-by-day forecast
The NWS point forecast for Murrieta shows a steep ramp-up starting Thursday:
- Thursday, Oct. 1: High 96°F / Low 64°F
- Friday, Oct. 2: High 101°F / Low 70°F
- Saturday, Oct. 3: High 102°F / Low 71°F
- Sunday, Oct. 4: High 101°F / Low 72°F
- Monday, Oct. 5: High 99°F / Low 70°F
- Tuesday, Oct. 6: High 99°F
Saturday's 102°F forecast marks the peak. The NWS said in its Tuesday, Sept. 29, forecast discussion that weekend highs across the western valleys could reach 15 to 20 degrees above average.
Overnight lows a concern
Overnight temperatures may pose as much risk as daytime heat. Murrieta's forecast lows of 70°F to 72°F from Friday night through Sunday night give the body little time to cool down. The NWS warned that valley locations could tie or break daily record-high minimum temperatures Saturday and Saturday, Oct. 3-4.
Periods of weak offshore winds with gusts of 25 to 35 mph are also expected along inland valleys over the Oct. 3-4 weekend, adding to heat stress.
How to stay safe
The NWS urged residents to drink plenty of fluids, stay in air-conditioned spaces, avoid the sun during peak afternoon hours and check on neighbors and pets.
Riverside County residents looking for relief can find cooling center locations and hours through the Community Action Partnership of Riverside County, which publishes a directory in English and Spanish along with an interactive map. Specific Murrieta locations were not confirmed at the time of publication.
No statements from Murrieta Fire and Rescue or the Murrieta Police Department regarding the heat event were available as of Wednesday, Sept. 30.
The Extreme Heat Watch expires at 9 p.m. Wednesday, Oct. 7, though the NWS has indicated the heat wave could persist beyond that date.
