Millions Issued Heat Wave Warning: 'Avoid Outdoor Activities'

Forecasters warn of dangerously high temperatures that will persist well beyond the weekend in Southern California.

Mar. 13, 2026 at 12:54pm

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A widespread and unusually intense heat wave is gripping much of Southern California, with the National Weather Service (NWS) warning that dangerously high temperatures will persist well beyond the weekend. Forecasters say temperatures will remain well above normal into next week, with the heat peaking on Friday but relief not expected anytime soon. Several calendar-day records are expected to fall, and some locations could challenge or exceed all-time March records next week.

Why it matters

Health officials warn that prolonged exposure to high temperatures significantly increases the risk of heat-related illness, especially for sensitive populations like young children, older adults, and those without access to air conditioning. The limited nighttime cooling may also compound the risks by preventing bodies from fully recovering after hot days.

The details

Daytime highs are forecast to run 15 to 30 degrees above seasonal averages, with temperatures in the mid-90s in coastal and inland areas of San Luis Obispo and Santa Barbara counties, and parts of Los Angeles, Ventura, and the San Fernando Valley expected to see highs between 90 and 100 degrees. Inland areas of Orange County, the Inland Empire, and San Diego County valleys are also climbing into the upper 80s and low 90s, with beaches offering only limited relief.

  • Heat advisories are in effect through 8 p.m. Friday for a wide swath of the region.
  • The heat is expected to intensify again early next week, with the most extreme temperatures expected from Tuesday through Thursday.

The players

National Weather Service (NWS)

The National Weather Service is urging residents to change daily routines now rather than waiting for conditions to worsen, and is advising people to limit strenuous outdoor activity between 10 a.m. and 8 p.m. when heat stress is highest.

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What’s next

Forecasters caution that additional heat advisories—or even extreme heat warnings—may be issued as the prolonged event continues into next week.

The takeaway

This heat wave highlights the growing threat of climate change and the need for communities to be prepared for more frequent and intense extreme weather events. Residents are urged to take immediate action to protect themselves and their loved ones from the dangers of prolonged exposure to high temperatures.