California, 2023

Heat in California, September 7 to 12, 2023

September 7 to 12, 2023 · NWS SGX · 7 events in 7 counties and zones

A short-duration heat wave impacted inland locations during the second weekend of September. The Coachella Valley saw readings up to 110-115 degrees on September 9, with lows only falling into the 90s.

Where it happened

Every event with a place to put it; 7 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

  • Tornadoes
  • Tropical storms and surge
  • Floods
  • Wind
  • Hail
  • Winter weather
  • Heat and drought
  • Cold
  • Fire, smoke and dust
  • Marine and coastal
  • Other

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The toll

Deaths
0
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
7

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS SGX wrote it up.

A short-duration heat wave impacted inland locations during the second weekend of September. The Coachella Valley saw readings up to 110-115 degrees on September 9, with lows only falling into the 90s. Elsewhere, the Inland Empire, the San Diego County Valleys and the High Desert saw highs in the upper-90s to low-100s each day.

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

7 heat. Local standard time, as filed.

Heat, San Diego County Deserts

When
September 7, 10:00 AM PST to September 12, 7:00 PM PST
Where
San Diego County Deserts forecast zone
Reported by
AWOS
Coordinates
33.028, -116.770 (the zone’s center; the record gives no point)

Hot temperatures impacted the Coachella Valley September 7-12, 2023. High temperatures reached the 100s to mid-110s each day, with overnight lows falling mainly into the 80s and 90s. The hottest temperatures occurred on September 9, when Borrego Springs reached 110 degrees.

Heat, Coachella Valley

When
September 7, 12:00 PM PST to September 12, 7:00 PM PST
Where
Coachella Valley forecast zone
Reported by
ASOS
Coordinates
33.744, -115.994 (the zone’s center; the record gives no point)

Hot temperatures impacted the Coachella Valley September 7-12, 2023. High temperatures reached the 100s to mid-110s each day, with overnight lows falling mainly into the 80s and 90s. The hottest temperatures occurred on September 9:

Palm Springs: 115/84|Indio: 112/94|Thermal Airport: 112/93.

Heat, Riverside County Mountains

When
September 8, 10:00 AM PST to September 9, 7:00 PM PST
Where
Riverside County Mountains forecast zone
Reported by
AWOS
Coordinates
33.744, -115.994 (the zone’s center; the record gives no point)

Hot temperatures impacted the Riverside County Mountains September 8-9, 2023. High temperatures reached the upper-80s to the mid-90s each day. The hottest temperatures occurred on September 9, when Anza reached 94 degrees, and Idyllwild reached 88 degrees.

Heat, San Bernardino and Riverside County Valleys - the Inland Empire

When
September 8, 10:00 AM PST to September 9, 7:00 PM PST
Where
San Bernardino and Riverside County Valleys - the Inland Empire forecast zone
Reported by
ASOS
Coordinates
34.293, -116.086 (the zone’s center; the record gives no point)

Hot temperatures impacted the Inland Empire September 8-9, 2023. High temperatures reached the upper-90s to the low-100s each day, with overnight lows falling into the 60s and 70s. The hottest temperatures occurred on September 8:

Ontario: 98/72|Chino: 102/69|Riverside Airport: 100/72|San Jacinto: 100/71|Temecula: 98/70|San Bernardino: 99/72.

Heat, San Diego County Valleys

When
September 8, 10:00 AM PST to September 10, 7:00 PM PST
Where
San Diego County Valleys forecast zone
Reported by
ASOS
Coordinates
33.028, -116.770 (the zone’s center; the record gives no point)

Hot temperatures impacted the San Diego County Valleys September 8-10, 2023. High temperatures reached the upper-90s, with overnight lows falling mainly into the 60s and 70s. The hottest temperatures occurred on September 8:

Ramona: 99/61|Poway: 97/66|Alpine: 96/69|Gillespie Field: 97/70|El Cajon: 97/70.

Heat, Apple and Lucerne Valleys

When
September 8, 12:00 PM PST to September 11, 6:00 PM PST
Where
Apple and Lucerne Valleys forecast zone
Reported by
AWOS
Coordinates
34.841, -116.178 (the zone’s center; the record gives no point)

Hot temperatures impacted the High Desert September 8-11, 2023. High temperatures reached the upper-80s to the upper-90s each day, with overnight lows falling into the 60s and 70s. The hottest temperatures occurred on September 9, when Apple Valley reached 99 degrees, and Hesperia reached 94 degrees.

Heat, Orange County Inland

When
September 9, 10:00 AM PST to 7:00 PM PST
Where
Orange County Inland forecast zone
Reported by
ASOS
Coordinates
33.677, -117.776 (the zone’s center; the record gives no point)

Hot temperatures impacted inland Orange County on September 9, 2023. High temperatures reached the upper-80s to the upper-90s, with overnight lows falling into the upper-60s and 70s. Highs/Lows from September 9:

Yorba Linda: 98/74|Los Alamitos: 92/69|Fullerton: 96/72|Santa Ana: 94/72|Lake Forest: 94/74.

What these are

Heat
Heat below excessive heat criteria that still caused deaths, injuries or significant impacts.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

More

Every storm in California in 2023Every state in 2023This day in weather historyWarnings in California, September 2023

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1139405, 1139364, 1139383, 1139404, 1139406, 1139353, 1139382.