An unusual October heat wave has put more than 35 million Californians under heat alerts, with temperatures up to 20 degrees above normal from the Bay Area to the Mexico border. Extreme heat warnings in Southern California run through 8 p.m. Thursday, October 8, after a string of daily temperature records fell over the weekend.
Key Takeaways
- Extreme heat warnings cover the coasts and valleys of Los Angeles, Ventura, Orange, Riverside, San Bernardino and San Diego counties through Thursday, October 8.
- Santa Ana reached 107 degrees and Anaheim 105 on Saturday, October 3, each breaking a daily record set in 2014.
- Vista, in northern San Diego County, hit 108 degrees, tying its all-time record high from June 30, 1985.
- The Bouquet Fire near Santa Clarita burned about 1,048 acres and was 48% contained by Sunday evening, with evacuation orders still in place.
- The California Independent System Operator (CAISO) issued a Restricted Maintenance Operations notice for Monday and Tuesday but said it does not expect supply shortfalls.
- Record-warm overnight lows in Orange County limited relief after dark.
Records Fall Across Southern California
The National Weather Service recorded new daily highs on both Friday and Saturday. On Friday, October 2, downtown Los Angeles, Long Beach Airport and Anaheim each hit 103 degrees, and Santa Ana reached 105, all records for the date.
Saturday was hotter. Hollywood Burbank Airport hit 102 degrees, beating a record from 1943. Anaheim reached 105 and Santa Ana 107, both well above their 2014 marks. San Diego also hit 105, one of at least eight Southern California cities to set daily records that day.
Highs on Sunday were near 104 in downtown Los Angeles and 103 in Bakersfield, with Sacramento and San Diego in the upper 90s. San Francisco and Sacramento were under heat advisories, an unusual situation for Northern California in October.
Warm Nights Add to the Health Risk
Overnight temperatures are a major concern in this heat wave. On Saturday night, the National Weather Service recorded record-warm lows of 76 degrees in Anaheim, 72 in Santa Ana and 70 in Newport Beach. When nights stay that warm, homes without air conditioning do not cool down, and heat stress builds over several days.
The Los Angeles County Department of Public Health advised residents to drink plenty of water, limit outdoor activity during the hottest hours, and use air-conditioned spaces or cooling centers if they cannot keep their homes cool. County officials said residents can call 211 to find cooling centers, splash pads and community pools. Officials in Orange, Riverside and San Bernardino counties have also opened cooling centers.
Older adults, young children, outdoor workers and people with chronic health conditions face the greatest risk of heat-related illness.
California’s Power Grid Is Under Watch
The California Independent System Operator, which manages most of the state’s grid, issued a Restricted Maintenance Operations notice from 10 a.m. to 10 p.m. on Monday and Tuesday. The notice asks power plant and transmission operators to postpone maintenance that could reduce available capacity.
CAISO said it does not currently forecast a supply shortfall and issued the notice so consumers would be prepared if it needs to call a Flex Alert. A Flex Alert asks Californians to voluntarily cut electricity use, usually in the late afternoon and evening when demand peaks and solar output falls.
Fire risk also affects the power system. Before the weekend, Southern California Edison said nearly 10,000 customers in parts of Riverside County were being considered for public safety power shutoffs, which cut electricity to lower the chance of equipment starting a fire.
Bouquet Fire Shows the Wildfire Risk
The heat is also drying out vegetation across the region. The Bouquet Fire started around 3 p.m. on Saturday, October 3, near Bouquet Canyon Road and Quarry Road in the Angeles National Forest, northeast of Santa Clarita. It grew to about 1,048 acres in steep, hard-to-reach chaparral and grass.
Cal Fire and the Angeles National Forest reported containment rising to 48% by Sunday evening as crews made progress on the southern edge of the fire. Evacuation orders remained in place for zones LAC-E018, LAC-E030-B and LAC-E031-A, and evacuation warnings covered nearby areas. Bouquet Canyon Road stayed closed between Spunky Canyon Road and Vasquez Canyon Road. An evacuation shelter is open at the Castaic Sports Complex on Castaic Road. The cause is under investigation.
What the Rest of the Week Looks Like
Extreme heat warnings in Southern California last until 8 p.m. Thursday, October 8, which makes this one of the longer October heat events on record for coastal areas. The heat is also spreading across the West, with highs in the upper 80s possible as far north as southern Idaho and Montana on Monday.
For California, the main concerns this week are the length of the heat wave, warm nights, and wildfire conditions in inland and mountain areas. Residents should follow National Weather Service updates, county emergency alerts and CAISO grid notices.
FAQs
How Long Will the California Heat Wave Last?
Extreme heat warnings for Los Angeles, Ventura, Orange, Riverside, San Bernardino and San Diego counties run through 8 p.m. Thursday, October 8. The National Weather Service may extend or adjust them.
Which California Cities Broke Temperature Records?
Santa Ana, Anaheim, San Diego, Hollywood Burbank Airport, downtown Los Angeles and Long Beach Airport set daily records over the weekend. Vista tied its all-time record high of 108 degrees.
Will There Be a Flex Alert in California?
CAISO has not issued a Flex Alert. It issued a Restricted Maintenance Operations notice for Monday and Tuesday and said it would update the public if conditions change.
Where Can Southern California Residents Find Cooling Centers?
Los Angeles County residents can call 211 to find cooling centers, splash pads and pools. Other Southern California counties have also opened cooling centers during the heat warnings.
Is the Bouquet Fire Contained?
The Bouquet Fire near Santa Clarita was 48% contained at about 1,048 acres as of Sunday evening. Evacuation orders and warnings remained in effect for nearby zones.
