8/11/2025 11:59:00 AM until 8/12/2025 5:00:00 PM

Drink plenty of fluids, stay in an air-conditioned location, avoid prolonged sun exposure, and check on relatives, neighbors, and pets. Limit strenuous activities to early morning or evening hours.

* WHAT...High temperatures ranging from 97-104 degrees in valleys and basins, with warmest lows between 65-70 degrees. Widespread Moderate to locally Major HeatRisk. * WHERE...In California, Lassen-Eastern Plumas-Eastern Sierra Counties and Surprise Valley California. In Nevada, Northern Washoe County, Western Nevada Basin and Range including Pyramid Lake, Greater Reno-Carson City-Minden Area, and Mineral and Southern Lyon Counties. * WHEN...Until 9 AM PDT Wednesday. * IMPACTS...Heat-related illnesses will be more likely, especially for those spending extended periods outdoors, in poorly cooled indoor spaces, or who are sensitive to heat. * ADDITIONAL DETAILS...Hottest conditions are expected Tuesday afternoon in lower valleys and basins. Cooler conditions above 4500 ft in Lassen-Eastern Plumas-Eastern Sierra counties and along foothill slopes outside the lower valleys.