Heat — North Bay Interior Valleys, California

2022-09-05 · North Bay Interior Valleys, California

Event narrative

Santa Rosa Coop site set a new monthly max temperature record of 112 deg., breaking the previous record of 110 deg recorded in 2020, 2017, and 1971. Napa Coop site set a new daily max temperature record of 109 deg., breaking the previous record of 102 deg. set in 2020. Kentfield Coop site set a new daily record of 107 deg., breaking the previous record of 103 deg., set in 1950.

Wider weather episode

A strong ridge of high pressure encompassed the Western CONUS from September 1st through 8th, leading to anomalously hot temperatures along the California coast, and even more extreme temperatures in interior valleys and all mountain zones, where very hot daytime temperatures combined with a lack of overnight cooling created extreme heat risk . Excessive Heat Warnings were issued for interior areas and mountains of Monterey/San Benito Counties for the period September 1st through 8th, and for interior valleys and mountain zones around the San Francisco Bay Area from September 4th through 8th. A combination of Heat Advisories and an Excessive Heat Warning was issued for parts of Monterey Bay and its near coastal valleys, the San Francisco Bay Shoreline, and Marin Coastal Mountains from September 4th through 8th, along with a Heat Advisory for the Central Coast, San Francisco, and coastal North Bay on September 6th. Several daily record high temperature records were shattered, along with a handful of monthly and all-time records. Triple digit temperatures were reported across a vast swath of the interior, with some sites reaching 110 degrees and higher. Reports of power outages, heat related illnesses and deaths were received. Counties opened/operated one or more cooling centers to provide relief from the heat.

Source: NOAA Storm Events Database, event_id 1055386. Narrative written by the NWS forecast office that issued the report.