Excessive Heat — East Bay Interior Valleys, California

2021-07-10 · East Bay Interior Valleys, California

Event narrative

Byron ASOS reached a daytime high of 113 degrees F and remained in the 100s until 8 pm PDT. Temperatures were still in the 80s by midnight.

Wider weather episode

Strong high pressure building over the region in early to mid July brought warm to hot temperatures across the interior. Daytime highs rose into the 100s with locations across the East Bay up to 110 degrees between July 9th and 11th. Overnight lows remained warm, particularly across higher elevations where temperatures were still in the 70s and 80s in the early mornings. Additionally, prolonged dry conditions resulted in near record dry fuels for July. This along with breezy afternoon winds prompted the Diablo Fire in Contra Costa County.

Source: NOAA Storm Events Database, event_id 966983. Narrative written by the NWS forecast office that issued the report.