California, 2023Excessive Heat and Dense Fog in California, August 28 to 30, 2023
August 28 to 30, 2023 · NWS SGX · 10 events in 10 counties and zones
An upper level area of high pressure caused very hot daytime temperatures to occur in late August 2023. It also caused the daily marine layer low clouds/fog to become more confined to the coast, which resulted in dense fog impacting San Diego International Airport for an extended period of time, resulting in a large number of delays.
Every event with a place to put it; 10 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
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- Deaths
- 0
- Injuries
- 0
- Property damage
- None recorded
- Crop damage
- None recorded
- Events
- 10
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.
An upper level area of high pressure caused very hot daytime temperatures to occur in late August 2023. It also caused the daily marine layer low clouds/fog to become more confined to the coast, which resulted in dense fog impacting San Diego International Airport for an extended period of time, resulting in a large number of delays.
Excessive Heat, San Bernardino and Riverside County Valleys - the Inland Empire
- When
- August 28, 11:00 AM PST to August 30, 8:00 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)
Very hot daytime temperatures occurred across the Inland Empire August 28-30th, when Excessive Heat Warnings were in effect. Highs between 100-107 occurred each afternoon, with the hottest temperatures occurring near Chino, Riverside, and San Bernardino.
Excessive Heat, San Diego County Valleys
- When
- August 28, 11:00 AM PST to August 30, 8:00 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)
Very hot daytime temperatures occurred across the San Diego County Valleys on August 28-30th, when Excessive Heat Warnings were in effect. Highs between 94-106 degrees occurred each afternoon, with the hottest temperatures occurring near Escondido, Ramona, and Poway.
Excessive Heat, Coachella Valley
- When
- August 28, 11:00 AM PST to August 30, 8:00 PM PST
- Where
- Coachella Valley forecast zone
- Reported by
- ASOS
- Coordinates
- 33.744, -115.994 (the zone’s center; the record gives no point)
Very hot daytime temperatures occurred across the Coachella Valley on August 28-30th, when Excessive Heat Warnings were in effect. Highs between 108-118 degrees occurred each afternoon, with the hottest temperatures occurring in Palm Springs.
Excessive Heat, San Diego County Deserts
- When
- August 28, 11:00 AM PST to August 30, 8:00 PM PST
- Where
- San Diego County Deserts forecast zone
- Reported by
- ASOS
- Coordinates
- 33.028, -116.770 (the zone’s center; the record gives no point)
Very hot daytime temperatures occurred across the San Diego County Deserts on August 28-30th, when Excessive Heat Warnings were in effect. Highs between 108-115 degrees occurred each afternoon, with the hottest temperatures occurring in Borrego Springs.
Excessive Heat, Orange County Inland
- When
- August 28, 11:00 AM PST to August 30, 8:00 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)
Very hot daytime temperatures occurred across inland portions of Orange County on August 28-30th, when Heat Advisories were in effect. Highs between 91 and 103 degrees occurred each day, with Yorba Linda and Anaheim seeing the hottest temperatures, both exceeding 100 degrees on the 28th and 29th.
Excessive Heat, San Bernardino County Mountains
- When
- August 28, 11:00 AM PST to August 30, 8:00 PM PST
- Where
- San Bernardino County Mountains forecast zone
- Reported by
- ASOS
- Coordinates
- 34.841, -116.178 (the zone’s center; the record gives no point)
Very hot daytime temperatures occurred across the San Bernardino County Mountains on August 28-30th, when Heat Advisories were in effect. Highs in the upper 80s to near 90 degrees occurred, with Wrightwood and Lake Arrowhead seeing the warmest temperatures.
Excessive Heat, Riverside County Mountains
- When
- August 28, 11:00 AM PST to August 30, 8:00 PM PST
- Where
- Riverside County Mountains forecast zone
- Reported by
- ASOS
- Coordinates
- 33.744, -115.994 (the zone’s center; the record gives no point)
Very hot daytime temperatures occurred across the Riverside County Mountains on August 28-30th, when Heat Advisories were in effect. Highs in the lower 90s to just over 100 degrees occurred, with Anza and Idyllwild seeing the warmest temperatures.
Excessive Heat, San Diego County Mountains
- When
- August 28, 11:00 AM PST to August 30, 8:00 PM PST
- Where
- San Diego County Mountains forecast zone
- Reported by
- ASOS
- Coordinates
- 33.028, -116.770 (the zone’s center; the record gives no point)
Very hot daytime temperatures occurred across the San Diego County Mountains on August 28-30th, when Heat Advisories were in effect. Highs in the lower to middle 90s occurred, with Julian seeing the warmest temperatures.
Excessive Heat, Santa Ana Mountains and Foothills
- When
- August 28, 11:00 AM PST to August 30, 8:00 PM PST
- Where
- Santa Ana Mountains and Foothills forecast zone
- Reported by
- ASOS
- Coordinates
- 33.483, -116.847 (the zone’s center; the record gives no point)
Very hot daytime temperatures occurred across the Santa Ana Mountains on August 28-30th, when Heat Advisories were in effect. Highs of 99 to 102 occurred near El Cariso during this time.
Dense Fog, San Diego County Coastal Areas
- When
- August 30, 2:50 AM PST to 8:00 AM PST
- Where
- San Diego County Coastal Areas forecast zone
- Reported by
- ASOS
- Coordinates
- 33.028, -116.770 (the zone’s center; the record gives no point)
Dense fog reducing visibility to as low as 1/4 SM occurring from roughly 3:50 AM to 9:00 AM PDT caused numerous delays at San Diego International Airport.
- Excessive Heat
- Heat at or above the local excessive heat warning criteria, or heat that caused deaths.
- Dense Fog
- Fog reducing visibility to a quarter mile or less, filed where it caused accidents or disruption.
After NWS Directive 10-1605, the rules offices file Storm Data by.
- Flash Flooding and Flooding in West Virginia, August 28, 2023$4.6 million · 9 events
- Flash Flooding and Flood in Georgia, August 28 to 29, 20231 injured · $285,000 · 50 kt wind · 42 events
- Wildfire in Louisiana, August 28, 2023$20,000 · 1 event
- Hail and Damaging Winds in Wisconsin, August 28, 2023$15,000 · 1 in hail · 5 events
- Flash Flooding in Virginia, August 28, 202311 events
- Flash Flooding in North Carolina, August 28, 2023$15,000 · 2 events
- Flash Flood and Damaging Winds in New Mexico, August 28, 202356 kt wind · 5 events
- Marine Thunderstorm Winds in Gulf of Mexico, August 28, 20233 events
- Hail and Damaging Winds in Colorado, August 28, 20231 in hail · 3 events
- Excessive Heat in Arizona, August 28 to 30, 20233 events
- Wildfire in Oklahoma, August 28 to 31, 20232 events
- Flash Flood and Flood in North Carolina, August 28, 2023$10,000 · 2 events
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 2026-09-30. Each event’s entry at NCEI: 1132649, 1132650, 1132651, 1132652, 1133792, 1133794, 1133795, 1133796, 1133798, 1133801.