Alert archive / California / Heat Advisories

Heat Advisories in California, 2021

55 heat advisories in 2021. 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 heat advisories reaches back to 2005.

Heat Advisories by county

Each county as a circle sized by its count in 2021. Tap one for its archive.

Heat Advisories: 55
Busiest month: June15 heat advisories
Busiest day: August 13, 20214 heat advisories

Over time

By month

The alerts

Every alert, in the order issued. Times are local, Pacific Time. Each opens its own page with the text, the map, the radar and the sounding.

Issued	Product	Office	Counties	Lasted
May 28, 12:41 PM PDT	Heat Advisory	MTR	Alameda, Contra Costa, Marin, Napa, Sonoma	3 days
May 28, 2:16 PM PDT	Heat Advisory	EKA	Lake, Mendocino, Trinity	4 days
May 29, 1:22 PM PDT	Heat Advisory	MFR	Siskiyou	4 days
May 31, 3:54 AM PDT	Heat Advisory	HNX		64 hr
Jun 2, 10:18 PM PDT	Heat Advisory	HNX		22 hr
Jun 14, 1:17 PM PDT	Heat Advisory	MTR	Alameda, Contra Costa, Marin, Monterey, Napa, San Benito and 4 more	4 days
Jun 14, 1:59 PM PDT	Heat Advisory	SGX	Orange	4 days
Jun 15, 3:13 AM PDT	Heat Advisory	EKA	Humboldt, Mendocino, Trinity	5 days
Jun 16, 2:47 AM PDT	Heat Advisory	LOX	Los Angeles	42 hr
Jun 17, 9:05 PM PDT	Heat Advisory	LOX	Los Angeles	48 hr
Jun 18, 9:06 PM PDT	Heat Advisory	MTR	Alameda, Contra Costa, Monterey, San Benito	23 hr
Jun 19, 9:21 PM PDT	Heat Advisory	EKA	Lake, Mendocino, Trinity	17 hr
Jun 24, 1:56 PM PDT	Heat Advisory	EKA	Humboldt, Lake, Mendocino, Trinity	5 days
Jun 25, 1:05 PM PDT	Heat Advisory	SGX	Riverside, San Bernardino	3 days
Jun 25, 1:34 PM PDT	Heat Advisory	LOX	Los Angeles	3 days
Jun 25, 1:44 PM PDT	Heat Advisory	REV	Lassen, Modoc, Plumas, Sierra	42 hr
Jun 29, 2:20 AM PDT	Heat Advisory	MFR	Modoc, Siskiyou	8 days
Jun 29, 2:01 PM PDT	Heat Advisory	EKA		31 hr
Jun 30, 3:10 AM PDT	Heat Advisory	REV	Lassen, Modoc, Plumas, Sierra	17 hr
Jul 7, 1:20 PM PDT	Heat Advisory	SGX	Riverside, San Bernardino, San Diego	5 days
Jul 7, 1:21 PM PDT	Heat Advisory	MFR	Modoc, Siskiyou	6 days
Jul 8, 8:47 AM PDT	Heat Advisory	MTR	Marin, Napa, Santa Clara, Sonoma	3 days
Jul 8, 2:18 PM PDT	Heat Advisory	LOX	Los Angeles	4 days
Jul 12, 8:39 AM PDT	Heat Advisory	HNX		35 hr
Jul 28, 9:50 AM PDT	Heat Advisory	EKA	Lake, Mendocino, Trinity	58 hr
Jul 30, 1:44 PM PDT	Heat Advisory	MFR	Siskiyou	4 days
Aug 1, 12:50 PM PDT	Heat Advisory	SGX	Riverside, San Bernardino, San Diego	4 days
Aug 2, 2:28 AM PDT	Heat Advisory	LOX	Los Angeles, Santa Barbara	66 hr
Aug 3, 8:02 PM PDT	Heat Advisory	LOX	Santa Barbara	24 hr
Aug 9, 11:28 AM PDT	Heat Advisory	MFR	Modoc, Siskiyou	4 days
Aug 10, 5:16 AM PDT	Heat Advisory	EKA	Humboldt, Lake, Mendocino, Trinity	57 hr
Aug 13, 10:59 AM PDT	Heat Advisory	LOX	Los Angeles	3 days
Aug 13, 12:50 PM PDT	Heat Advisory	HNX		47 hr
Aug 13, 1:26 PM PDT	Heat Advisory	EKA	Lake, Mendocino	55 hr
Aug 13, 1:46 PM PDT	Heat Advisory	STO		56 hr
Aug 14, 1:46 AM PDT	Heat Advisory	REV	Modoc	69 hr
Aug 14, 12:17 PM PDT	Heat Advisory	MFR	Siskiyou	35 hr
Aug 24, 1:30 PM PDT	Heat Advisory	SGX	Riverside, San Bernardino, San Diego	5 days
Aug 26, 1:06 AM PDT	Heat Advisory	EKA	Lake, Mendocino	4 days
Aug 27, 3:25 AM PDT	Heat Advisory	LOX	Los Angeles, Santa Barbara	4 days
Aug 27, 12:33 PM PDT	Heat Advisory	HNX		56 hr
Sep 3, 1:18 PM PDT	Heat Advisory	SGX	Orange, Riverside, San Bernardino, San Diego	9 days
Sep 4, 3:40 AM PDT	Heat Advisory	HNX		64 hr
Sep 4, 1:48 PM PDT	Heat Advisory	LOX	Los Angeles, Santa Barbara	6 days
Sep 5, 11:29 AM PDT	Heat Advisory	STO		3 days
Sep 5, 12:07 PM PDT	Heat Advisory	HNX		56 hr
Sep 5, 8:10 PM PDT	Heat Advisory	LOX	Los Angeles	24 hr
Sep 6, 1:55 AM PDT	Heat Advisory	HNX		67 hr
Sep 6, 10:01 AM PDT	Heat Advisory	HNX		3 days
Sep 7, 1:13 PM PDT	Heat Advisory	SGX	San Diego	5 days
Sep 8, 7:50 AM PDT	Heat Advisory	EKA	Lake	12 hr
Sep 8, 7:50 AM PDT	Heat Advisory	HNX	Fresno, Kern, Kings, Madera, Mariposa, Merced and 1 more	36 hr
Sep 11, 2:35 AM PDT	Heat Advisory	LOX	Los Angeles	17 hr
Sep 20, 12:33 PM PDT	Heat Advisory	SGX	Orange, Riverside, San Bernardino, San Diego	55 hr
Sep 20, 1:25 PM PDT	Heat Advisory	LOX	Los Angeles	55 hr

By county

Every county with at least one alert. A county page lists each alert that covered it.

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force now Tornadoes on record The radar archive 2020 2022

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. Rebuilt daily.