The National Weather Service issued a heat advisory for much of the Bay Area, including most of Alameda County, beginning at noon Thursday, while a Severe Extreme Heat Warning was in effect for portions of Northern California through June 16, 2026, at 11:00 p.m. The advisory and warning covered inland zones expected to reach triple-digit temperatures in the Bay Area and up to 110 degrees in the Northern Sacramento Valley, Western Tehama County Foothills, Western Shasta County Foothills, South-Central Shasta County, and the Sierra Nevada of Tehama–Butte–Plumas counties. Last update: June 12, 2026.
Officials stated the alerts were issued due to dangerously hot conditions and a widespread Major HeatRisk that can rapidly elevate the chance of heat-related illness. Inland communities without reliable cooling were identified as most vulnerable, with agencies urging people to limit afternoon exposure, stay hydrated, and use air-conditioned spaces where possible. Emergency guidance included dialing 911 for signs of heat stroke, and checking on older adults, individuals with chronic conditions, and unhoused residents.
Bay Area advisory and inland temperatures
Forecasters indicated the Bay Area advisory began at noon Thursday for interior locations, with inland highs expected to reach the triple digits. Alameda County and surrounding inland corridors were highlighted for peak heat during afternoon hours, while coastal zones were likely to remain relatively cooler. Agencies emphasized planning outdoor work for early morning or evening, wearing lightweight, loose-fitting clothing, and maintaining frequent water intake to reduce heat stress.
Severe warning through June 16 in Northern California
The Severe Extreme Heat Warning covered Northern Sacramento Valley areas in Tehama County and Butte County, plus adjacent foothills and Sierra Nevada zones, and was scheduled to remain in place until June 16, 2026, at 11:00 p.m.. Temperatures up to 110 degrees were expected, with little overnight relief in some interior valleys, increasing cumulative health risks. Authorities advised residents to move activities indoors where possible and to use community cooling sites to mitigate prolonged exposure during the warning period.
Cooling centers, service adjustments, and community response
Local departments and community organizations activated cooling centers for residents without air conditioning, offering shaded rest areas and water. Fire officials urged vigilance around wildfire ignition sources during the hottest hours, while schools reported heat-safety protocols and businesses adjusted hours to avoid peak afternoon heat. Volunteer groups organized water distribution and welfare checks, reinforcing recommendations to monitor pets, secure shade, and ensure continuous access to cool water as the heat wave continues across the affected regions.
