Flex Alert Urged This Week Due to Extreme Heat

The California Independent System Operator (Cal ISO) issued a statewide Flex Alert today that calls for voluntary electricity conservation from 5 p.m. to 9 p.m. on July 24 (Tuesday) and July 25 (Wednesday).

Consumers are urged to conserve electricity especially during the afternoon when air conditioners typically are at peak use, as well as turn off all unnecessary lights, use major appliances before 5 p.m. and after 9 p.m., and set air conditioners to 78 degrees or higher to avoid any interruptions.

The ISO has issued the Flex Alert due to high temperatures across the western U.S., reduced electricity imports, tight natural gas supplies in the Southern California area and high wildfire risk. A Flex Alert is issued by the ISO when the electricity grid is under stress because of generation or transmission outages, or from persistent hot temperatures.

The ISO has called on all available resources to be available to serve demand, however conservation is needed to reduce the risk of further emergency measures including rotating power outages.


Conservation tips include:

  • Set thermostat at 78 degrees or higher and turn off, if away
  • Cool with fans and draw drapes
  • Turn off unnecessary lights and appliances
  • Use major appliances in morning or late evening

A grid operator monitors the daily forecast and has the ability to notify businesses, local governments, residents and state agencies by media reports or emails. These alerts are typically regionally targeted and grid operators can shift energy resources within different regions to handle anticipated demands.


Extreme Heat Warning

Excessive heat warnings and a Red Flag Warning have been issued for Southern California. Successive days of extreme heat begins Tuesday in Southern California and could extend into Friday. Strong winds with gusts of 40 mph combined with extreme heat contributed to a Red Flag Warning being issued for Santa Barbara County through Thursday morning.

Poor overnight recovery is contributing to the need for a Flex Alert. Tuesday and Wednesday are expected to be the hottest days this week, with temperatures exceeding 100 degrees and only cooling down to the high 80s/low 90s overnight.

While Southern California is the epicenter of this specific heat event because of its intensity and duration, extreme heat is also in the forecast for Central and Northern California. Isolated afternoon thunderstorms are possible near the Sierra Nevada crest through midweek, while smoke and haze continue to be an issue for areas near the Ferguson fire.

Cal OES has activated its Southern Region Operations Center and the Inland Region Operations Center to closely monitor the heat event and to coordinate resources.


Get Flex Alert Notifications

  • To be notified immediately of a Flex Alert, click here.


Additional Resources


Jonathan Gudel

Jonathan Gudel is a Public Information Officer for the California Governor's Office of Emergency Services (Cal OES). Since joining Cal OES, he has assisted in the response and recovery efforts of the Aliso Canyon Gas Leak, the state's historic drought, the Oroville Dam Emergency Spillway Incident, unprecedented winter storms in 2017, the October (Sonoma County) and December (Santa Barbara County) 2017 wildfires, and statewide wildfire siege in 2018 . Previously, he worked in the newspaper industry for 12 years.

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