* WHAT. Dangerously hot conditions with high temperatures from 105 to 115, locally higher. Limited overnight relief with low temperatures in the mid 60s to mid 80s. Widespread Major to Extreme HeatRisk is expected. * WHERE. Carquinez Strait and Delta, Sacramento Valley, Northern San Joaquin Valley, Motherlode, Mountains Southwestern Shasta County to Western Colusa County, Northeast Foothills, Shasta Lake Area / Northern Shasta County. * WHEN. Until 11 PM PDT Tuesday. * IMPACTS. Heat related illnesses increase significantly during extreme heat events, particularly for those working outside or participating in outdoor activities. * ADDITIONAL DETAILS. Heat could significantly impact outdoor activities. Area waterways will continue to run cold and fast, creating dangerous conditions for those seeking relief in rivers and lakes. Delta breeze influence will result in slightly cooler, but still hot temperatures in the Delta and western portions of the Sacramento Area early this week.

* WHAT. Hot conditions with high temperatures up to 95-110. Areas of Major to Extreme HeatRisk are expected. * WHERE. Burney Basin / Eastern Shasta County, West Slope Northern Sierra Nevada, and Western Plumas County/Lassen Park. * WHEN. Until 11 PM PDT Tuesday. * IMPACTS. Heat related illnesses increase significantly during extreme heat events, particularly for those working outside or participating in outdoor activities. * ADDITIONAL DETAILS. Heat could significantly impact outdoor activities. Area waterways will continue to run cold and fast, creating dangerous conditions for those seeking relief in rivers and lakes.

* WHAT. Hot daytime temperatures in the 90s to near 100 this weekend into most of next week, will result in a prolonged period of Moderate to Major HeatRisk and heat health impacts for those sensitive to heat or those without access to effective cooling. * WHERE. Greater Lake Tahoe Area, Surprise Valley California, Lassen-Eastern Plumas-Eastern Sierra Counties, and Mono County. * WHEN. Until 10 AM PDT Friday. * IMPACTS. Heat related illnesses increase significantly during prolonged heat events, particularly for those working or participating in outdoor activities.