# Southern California heat wave > Live situation record from CLSTR: https://clstr.news/situations/southern-california-heat-wave > Updated: 2026-10-01T23:20:25.000Z. Sources: 19. Developments: 3. Southern California has faced a prolonged and dangerous heat wave characterized by triple-digit temperatures. Initially, the National Weather Service issued extreme heat watches for regions including Orange, Riverside, and Santa Barbara counties, warning of a high-pressure dome that could drive temperatures above 100 degrees in inland valleys and deserts. This period also brought increased wildfire risks and potential public safety power shut-offs in areas like Moreno Valley. As the event progressed, the National Weather Service upgraded alerts to Extreme Heat Warnings for coastal and valley areas of Los Angeles and Orange counties. In Los Angeles County, valley temperatures were forecast to reach between 90 and 105 degrees, while Saturday was projected to be the hottest day with valley temperatures potentially ranging from 100 to 107 degrees. In Orange County, inland areas were expected to see highs near 100 degrees. In Santa Barbara County, the Health Department issued a health alert following National Weather Service warnings covering south coast communities, the interior wilderness, and the Cuyama Valley. Health officials warned of elevated fire conditions and urged residents to prevent heat exhaustion and heat stroke by staying hydrated and seeking air-conditioned environments, noting that electric fans may not prevent illness when temperatures exceed the high 90s. The heat wave is forecast to persist from Friday through at least next Thursday. The combination of high temperatures, low humidity, and Santa Ana winds has significantly increased wildfire risks. Consequently, utility companies are preparing for potential Public Safety Power Shutoffs (PSPS). San Diego Gas & Electric Co. has flagged potential outages for more than 35,000 customers in at-risk communities, while Edison International is considering preventive shutoffs for nearly 10,000 customers in Riverside County. ## Claims - The National Weather Service has issued an Extreme Heat Warning for portions of San Diego and Los Angeles counties. (corroborated by 4 sources) - San Diego Gas & Electric Co. may implement Public Safety Power Shutoffs for over 35,000 customers due to wildfire risk. (corroborated by 4 sources) - The heat wave is expected to last from Friday through at least the following Thursday. (corroborated by 4 sources) - Temperatures in inland valleys are forecast to reach between 100 and 107 degrees Fahrenheit. (corroborated by 3 sources) - Edison International is considering preventive power shutoffs for approximately 9,990 customers in Riverside County. (corroborated by 2 sources) - Santa Ana winds are contributing to increased wildfire danger across Southern California. (corroborated by 2 sources) - The California Independent System Operator issued a notice to avoid maintenance that could jeopardize grid availability. (single source) - A wind advisory has been issued for San Bernardino and Riverside County valleys with gusts up to 45 mph. (single source) ## Timeline ### 2026-10-01: Santa Barbara County issues health alert for extreme heat Santa Barbara County Health Department has issued a health alert due to extreme heat warnings, with temperatures expected to reach up to 103 degrees in some areas. 2 sources. https://clstr.news/cluster/santa-barbara-county-issues-health-alert-for-extreme-heat ### 2026-10-01: Southern California faces extreme heat and wildfire risks Southern California faces a prolonged heat wave with temperatures reaching triple digits, prompting extreme heat warnings, increased wildfire risks, and potential utility power shutoffs. 15 sources. https://clstr.news/cluster/southern-california-heat-wave-to-bring-triple-digit-temperatures ### 2026-09-28: Southern California braces for major heat wave and triple-digit temperatures A significant heat wave is sweeping across Southern California, bringing triple-digit temperatures and extreme heat risks to inland valleys, mountains, and desert regions through next week. 3 sources. https://clstr.news/cluster/heat-waves-forecast-for-southern-california-and-dc-region --- Cite as: Southern California heat wave. CLSTR, https://clstr.news/situations/southern-california-heat-wave