Excessive Heat Watches in California
413 excessive heat watches since 1986. An alert counts here when it covered any part of the state, so the counties below add up to more than the state. The archive of excessive heat watches reaches back to 2005.
Excessive Heat Watches by county
Each county as a circle sized by its count since 1986. Tap one for its archive.
- Excessive Heat Watches
- 413
- Busiest year
- 202154 excessive heat watches
- Average year
- 22over 19 years on file
Over time
By year
Before late 2005 the archive holds only tornado, severe thunderstorm, flash flood and marine warnings, and from 1997 SPC's watches, so the jump that year is the archive widening, not the weather.
By month of the year
By county
Every county with at least one alert. A county page lists each alert that covered it.
- San Bernardino County146
- Riverside County101
- Inyo County62
- San Diego County61
- Los Angeles County54
- Imperial County42
- Santa Barbara County31
- Siskiyou County19
- Alameda County18
- Contra Costa County18
- Monterey County18
- San Benito County18
- Orange County18
- Santa Clara County17
- Ventura County17
- Napa County15
- Sonoma County15
- Marin County14
- San Mateo County14
- Santa Cruz County14
- Mendocino County13
- Kern County13
- San Luis Obispo County13
- Trinity County12
- Fresno County12
- Tulare County12
- Kings County12
- Lake County11
- Madera County11
- Mariposa County11
- Merced County11
- Humboldt County9
- Modoc County8
- City and County of San Francisco7
- Del Norte County6
- Lassen County4
- Plumas County4
- Sierra County4
Nearby
Sources
National Weather Service watches, warnings, advisories and statements from the Iowa Environmental Mesonet's VTEC archive, which reconstructs tornado, severe thunderstorm, flash flood and marine warnings back to 1986 from the NWS text archive. Storm Prediction Center watches and mesoscale discussions from SPC's archive through the Mesonet. County centers from the US Census Bureau. Warning verification from the Mesonet's Cow. Rebuilt daily.