* WHAT. Dangerously hot conditions with high temperatures from 103 to 117. Limited overnight relief with low temperatures in the upper 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, and 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 or participating in outdoor activities. * ADDITIONAL DETAILS. Heat could significantly impact outdoor holiday 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 Vicinity Delta and western portions of the Sacramento Area by late weekend into early next week.

* WHAT. Hot conditions with high temperatures up to 95-110. Limited overnight relief with low temperatures in the upper 50s to upper 70s. Areas of Major and 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 or participating in outdoor activities. * ADDITIONAL DETAILS. Heat could significantly impact outdoor holiday activities. Area waterways will continue to run cold and fast, creating dangerous conditions for those seeking relief in rivers and lakes.

* WHAT. Dangerously hot conditions with high temperatures from 100 to 118. 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, and 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 or participating in outdoor activities. * ADDITIONAL DETAILS. Heat could significantly impact outdoor holiday 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 Vicinity Delta and western portions of the Sacramento Area by late weekend into early next week.

* WHAT. Hot conditions with high temperatures up to 95-110. Limited overnight relief with low temperatures in the upper 50s to upper 70s. Areas of Major and 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 or participating in outdoor activities. * ADDITIONAL DETAILS. Heat could significantly impact outdoor holiday 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 next week will result in a prolonged period of Moderate 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. From 10 AM Saturday to 10 AM PDT Wednesday. * IMPACTS. Heat related illnesses increase significantly during heat events, particularly for those working or participating in outdoor activities.