California County Alert Archives from the National Weather Service

Alert Archives for All California Counties

If there's no Alerts for the day, there's no log file

Select a date: 26 total alerts issued on this day Updates Every 15 Minutes
Alert Summary \| Alert RSS Feed \| Alert Archives \| Icon key Last Update:August 21, 2026 - 7:00 am PDT

Imperial County

EXTREME HEAT WARNING
Areas affected: Parker Valley; Kofa; Yuma; Central La Paz; Southeast Yuma County; Gila River Valley; Imperial County Southwest; Imperial County Southeast; Imperial County West; Imperial Valley; Palo Verde Valley; Chuckwalla Valley
Effective: Aug 20 11:06 pm	Expired: Aug 21 3:00 pm	Duration: 15 hrs 54 mins

Riverside County

EXTREME HEAT WARNING (3 updates)
Areas affected: Parker Valley; Kofa; Yuma; Central La Paz; Southeast Yuma County; Gila River Valley; Imperial County Southwest; Imperial County Southeast; Imperial County West; Imperial Valley; Palo Verde Valley; Chuckwalla Valley
Effective: Aug 20 11:06 pm	Expired: Aug 21 3:00 pm	Duration: 15 hrs 54 mins
Areas affected: Coachella Valley; San Diego County Deserts; San Gorgonio Pass Near Banning
Effective: Aug 20 7:39 pm	Expired: Aug 21 6:15 am	Duration: 10 hrs 36 mins
Areas affected: Coachella Valley; San Diego County Deserts; San Gorgonio Pass Near Banning
Effective: Aug 21 1:42 am	Expired: Aug 21 3:30 pm	Duration: 13 hrs 48 mins

Inyo County

EXTREME HEAT WARNING (3 updates)
Areas affected: Lake Havasu and Fort Mohave; Lake Mead - AZ side; Lake Mohave - AZ side; Hualapai Mountains; Northwest Deserts; Death Valley National Park; Eastern Mojave Desert, Including the Mojave National Preserve; Morongo Basin; Cadiz Basin; San Bernardino County-Upper Colorado River Valley; Northeast Clark County; Western Clark and Southern Nye County; Las Vegas Valley; Southern Clark County; Lake Mead - NV side; Lake Mohave - NV side
Effective: Aug 20 4:57 am	Expired: Aug 21 5:00 am	Duration: 1 day 0 hrs 03 mins
Areas affected: Lake Havasu and Fort Mohave; Lake Mead - AZ side; Lake Mohave - AZ side; Northwest Deserts; Death Valley National Park; San Bernardino County-Upper Colorado River Valley; Las Vegas Valley; Lake Mead - NV side; Lake Mohave - NV side
Effective: Aug 21 3:55 am	Expired: Aug 21 8:00 pm	Duration: 16 hrs 05 mins
Areas affected: Lake Havasu and Fort Mohave; Lake Mead - AZ side; Lake Mohave - AZ side; Northwest Deserts; Death Valley National Park; San Bernardino County-Upper Colorado River Valley; Las Vegas Valley; Lake Mead - NV side; Lake Mohave - NV side
Effective: Aug 21 4:05 am	Expired: Aug 21 8:00 pm	Duration: 15 hrs 55 mins

San Bernardino County

EXTREME HEAT WARNING (5 updates)
Areas affected: Lake Havasu and Fort Mohave; Lake Mead - AZ side; Lake Mohave - AZ side; Hualapai Mountains; Northwest Deserts; Death Valley National Park; Eastern Mojave Desert, Including the Mojave National Preserve; Morongo Basin; Cadiz Basin; San Bernardino County-Upper Colorado River Valley; Northeast Clark County; Western Clark and Southern Nye County; Las Vegas Valley; Southern Clark County; Lake Mead - NV side; Lake Mohave - NV side
Effective: Aug 20 4:57 am	Expired: Aug 21 5:00 am	Duration: 1 day 0 hrs 03 mins
Areas affected: Lake Havasu and Fort Mohave; Lake Mead - AZ side; Lake Mohave - AZ side; Northwest Deserts; Death Valley National Park; San Bernardino County-Upper Colorado River Valley; Las Vegas Valley; Lake Mead - NV side; Lake Mohave - NV side
Effective: Aug 21 3:55 am	Expired: Aug 21 8:00 pm	Duration: 16 hrs 05 mins
Areas affected: Hualapai Mountains; Eastern Mojave Desert, Including the Mojave National Preserve; Morongo Basin; Cadiz Basin; Northeast Clark County; Western Clark and Southern Nye County; Southern Clark County
Effective: Aug 21 3:55 am	Expired: Aug 21 8:00 pm	Duration: 16 hrs 05 mins
Areas affected: Lake Havasu and Fort Mohave; Lake Mead - AZ side; Lake Mohave - AZ side; Northwest Deserts; Death Valley National Park; San Bernardino County-Upper Colorado River Valley; Las Vegas Valley; Lake Mead - NV side; Lake Mohave - NV side
Effective: Aug 21 4:05 am	Expired: Aug 21 8:00 pm	Duration: 15 hrs 55 mins
Areas affected: Hualapai Mountains; Eastern Mojave Desert, Including the Mojave National Preserve; Morongo Basin; Cadiz Basin; Northeast Clark County; Western Clark and Southern Nye County; Southern Clark County
Effective: Aug 21 4:05 am	Expired: Aug 21 8:00 pm	Duration: 15 hrs 55 mins

Lassen County

FIRE WEATHER WATCH
The National Weather Service in Reno has issued a Fire Weather
Areas affected: Surprise Valley California; Eastern Lassen County; Northern Washoe County
Effective: Aug 20 10:52 am	Expired: Aug 21 11:00 am	Duration: 1 day 0 hrs 08 mins

Modoc County 2 alerts

FIRE WEATHER WATCH (3 updates)
The National Weather Service in Reno has issued a Fire Weather
Areas affected: Surprise Valley California; Eastern Lassen County; Northern Washoe County
Effective: Aug 20 10:52 am	Expired: Aug 21 11:00 am	Duration: 1 day 0 hrs 08 mins
The National Weather Service in Medford has issued a Red Flag
Areas affected: Siskiyou County from the Cascade Mountains East and South to Mt Shasta; Modoc County Except for the Surprise Valley
Effective: Aug 20 9:02 pm	Expired: Aug 21 6:00 am	Duration: 8 hrs 58 mins
Areas affected: Siskiyou County from the Cascade Mountains East and South to Mt Shasta; Modoc County Except for the Surprise Valley
Effective: Aug 21 4:09 am	Expired: Aug 21 8:00 pm	Duration: 15 hrs 51 mins

RED FLAG WARNING (2 updates)
The National Weather Service in Medford has issued a Red Flag
Areas affected: Siskiyou County from the Cascade Mountains East and South to Mt Shasta; Modoc County Except for the Surprise Valley
Effective: Aug 20 9:02 pm	Expired: Aug 21 6:00 am	Duration: 8 hrs 58 mins
Areas affected: Siskiyou County from the Cascade Mountains East and South to Mt Shasta; Modoc County Except for the Surprise Valley
Effective: Aug 21 4:09 am	Expired: Aug 21 8:00 pm	Duration: 15 hrs 51 mins

Siskiyou County 2 alerts

RED FLAG WARNING (4 updates)
The National Weather Service in Medford has issued a Red Flag
Areas affected: Siskiyou County from the Cascade Mountains East and South to Mt Shasta; Modoc County Except for the Surprise Valley
Effective: Aug 20 9:02 pm	Expired: Aug 21 6:00 am	Duration: 8 hrs 58 mins
A Red Flag Warning has also been issued from 2 PM to 9 PM PDT
Areas affected: Central Siskiyou County Including Shasta Valley
Effective: Aug 20 9:02 pm	Expired: Aug 21 6:00 am	Duration: 8 hrs 58 mins
Areas affected: Siskiyou County from the Cascade Mountains East and South to Mt Shasta; Modoc County Except for the Surprise Valley
Effective: Aug 21 4:09 am	Expired: Aug 21 8:00 pm	Duration: 15 hrs 51 mins
A Red Flag Warning has also been issued from 2 PM to 9 PM PDT
Areas affected: Central Siskiyou County Including Shasta Valley
Effective: Aug 21 4:09 am	Expired: Aug 21 8:00 pm	Duration: 15 hrs 51 mins

FIRE WEATHER WATCH (2 updates)
The National Weather Service in Medford has issued a Red Flag
Areas affected: Siskiyou County from the Cascade Mountains East and South to Mt Shasta; Modoc County Except for the Surprise Valley
Effective: Aug 20 9:02 pm	Expired: Aug 21 6:00 am	Duration: 8 hrs 58 mins
Areas affected: Siskiyou County from the Cascade Mountains East and South to Mt Shasta; Modoc County Except for the Surprise Valley
Effective: Aug 21 4:09 am	Expired: Aug 21 8:00 pm	Duration: 15 hrs 51 mins

San Diego County

EXTREME HEAT WARNING (2 updates)
Areas affected: Coachella Valley; San Diego County Deserts; San Gorgonio Pass Near Banning
Effective: Aug 20 7:39 pm	Expired: Aug 21 6:15 am	Duration: 10 hrs 36 mins
Areas affected: Coachella Valley; San Diego County Deserts; San Gorgonio Pass Near Banning
Effective: Aug 21 1:42 am	Expired: Aug 21 3:30 pm	Duration: 13 hrs 48 mins

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