A trio of heat advisories has been issued for large swaths of California, with forecasters warning of dangerously high temperatures and heightened risks of heat-related illness. The advisories, released Thursday morning by separate National Weather Service offices, cover coastal, inland, and valley regions. They take effect Saturday at 11 a.m. and last through at least Sunday evening.
The NWS San Francisco CA issued its advisory at 9:43 a.m. Thursday, valid from Saturday 11 a.m. until Sunday 10 p.m. It encompasses the Sonoma Coastal Range, North Bay Interior Mountains, San Francisco Bay Shoreline, East Bay Interior Valleys, Santa Cruz Mountains, Santa Clara Valley including San Jose, Eastern Santa Clara Hills, East Bay Hills, Southern Salinas Valley/Arroyo Seco and Lake San Antonio, Santa Lucia Mountains and Los Padres National Forest, as well as Monterey County. Temperatures are expected to reach the middle 90s to near 103 degrees. Mild lows in the upper 60s to middle 70s at higher elevations will limit overnight recovery, the NWS said. “This level of heat affects anyone without effective cooling and/or adequate hydration,” the agency warned, noting likely impacts on some health systems, heat-sensitive industries, and infrastructure.
In the Sacramento region, the NWS Sacramento CA issued a heat advisory at 9:34 a.m. Thursday. It runs from Saturday 11 a.m. until Monday 10 p.m. The advisory covers a vast area: the Northern, Central, and Southern Motherlode between 1000-3000 ft; Central Colusa County including Interstate 5; Eastern Colusa County; Sutter and Yuba counties below 1000 ft; the Capay Hills of Yolo County and Vaca Hills of Solano County; Western Yolo County including Capay Valley and Interstate 505; Central Yolo and Northeast Solano counties including Woodland and Davis; Sacramento Metro and Western El Dorado and Amador counties; Central Solano County including Fairfield and Vacaville; Southwestern Solano County including Vallejo; Sacramento County Delta; San Joaquin County Delta; Central San Joaquin County including Stockton Metro; Tracy Triangle below 1000 ft; Northeastern San Joaquin Valley below 1000 ft; Eastern Diablo Range above 1000 ft; Western Stanislaus County below 1000 ft including Interstate 5; and Central Stanislaus County including Modesto Metro. High temperatures of 94 to 100 degrees are expected, with widespread Moderate HeatRisk and areas of Major HeatRisk. The hottest days are forecast for Sunday and Monday. “Hot temperatures may cause heat illnesses,” the NWS cautioned.
Further south, the NWS Hanford CA released a heat advisory at 9:30 a.m. Thursday, effective from Saturday 11 a.m. until Sunday 10 p.m. This advisory covers the West Side Mountains north of 198; Los Banos – Dos Palos; Merced – Madera – Mendota; Planada – Le Grand – Snelling; Coalinga – Avenal; West Side of Fresno and Kings counties; Fresno area; Fresno-Clovis; West Side Mountains South of 198; Delano-Wasco-Shafter; Hanford – Corcoran – Lemoore; Visalia – Porterville – Reedley; Bakersfield; Southeast San Joaquin Valley; South End San Joaquin Valley; Mariposa Madera Foothills; Mariposa-Madera Lower Sierra; Fresno-Tulare Foothills; Fresno-Tulare Lower Sierra; South End Sierra Foothills; and South End of the Lower Sierra, as well as Kern and Buena Vista counties. Temperatures could reach up to 103 degrees. The NWS warned of a “moderate to major risk of heat-related illnesses for much of the population, especially those without effective cooling or hydration.” As with the other advisories, the agency noted that “hot temperatures may cause heat illnesses.”
All three advisories emphasize safety measures. The Occupational Safety and Health Administration (OSHA) recommends frequent rest breaks in shaded or air-conditioned environments for outdoor workers. If someone shows signs of heat illness, move them immediately to a cool, shaded area. In an emergency, call 911.
