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OCINT

Independent civic dashboard for Orange County · AI briefings from public feeds · Not an emergency service (call 911) · Not government / not OCIAC · About

RESOLVEDSEV 2 · MODERATEENVIRONMENTUPDATED about 1 month ago
▸ SITUATION

Extreme Heat Warning for Orange County Sept. 8–10, Heat Advisory Through Sept. 11; Relief Arrives Sept. 15

The Extreme Heat Warning and subsequent Heat Advisory affecting all of Orange County from Sept. 8–11, 2026 have fully expired; cooler conditions arrived Sept. 15 as a low-pressure system settled over Southern California. The event is resolved with no further NWS heat products in effect.

MACHINE-READABLE markdown · JSON

CITIES AFFECTED
COUNTYWIDE
STARTED
about 2 months ago
Sep 8, 2026, 10:00 PT
EVIDENCE
15 items · 1 area
SITUATION MAP
1 area · 15 signals
WHO

NWS San Diego issued and managed the warning products; the City of Santa Ana and Southern California Edison responded to heat-related power outages; all county residents — especially those without air conditioning, outdoor workers, elderly, and young children — were the affected population.

WHAT

An Extreme Heat Warning (Sept. 8–10) followed by a Heat Advisory (through Sept. 11) covered all of Orange County, with inland highs reaching 100–106°F and heat-related power outages darkening traffic signals in Santa Ana.

WHERE

Countywide — Orange County Coastal Areas, Orange County Inland Areas, and the Santa Ana Mountains and Foothills; power-outage signals specifically at Main St. & MacArthur Blvd. and Newhope St. & 1st St. in Santa Ana.

WHEN

Heat Advisory effective 10 a.m. Sept. 8, 2026; upgraded to Extreme Heat Warning by 6:52 a.m. the same day; extended through Sept. 10; final Heat Advisory expired 8 p.m. Sept. 11; cooling relief arrived Sept. 15.

WHY

A prolonged high-pressure ridge drove extreme above-normal temperatures across Southern California; the event ended when a low-pressure system displaced the ridge around Sept. 15.

▸ NARRATIVE
Current Status

All NWS heat products for Orange County have expired. The Extreme Heat Warning that ran from Sept. 8 through 8 p.m. Sept. 10, 2026 and the follow-on Heat Advisory through 8 p.m. Sept. 11 are no longer in effect. ABC7 reports that a low-pressure system settled over Southern California on Tuesday, Sept. 15, bringing the heat event to a close.

Event Summary

What began as a Heat Advisory issued Sept. 7 by NWS San Diego was upgraded to an Extreme Heat Warning by 6:52 a.m. Sept. 8, covering Orange County coastal and inland zones. Inland highs reached 100 to 106°F on Wednesday, Sept. 9, with overnight lows holding in the 70s — limiting overnight recovery. NWS extended the Extreme Heat Warning through 8 p.m. Thursday, Sept. 10 (inland highs 90–100; NWS HeatRisk rated Major to Extreme), then issued a final Heat Advisory for inland areas through 8 p.m. Friday, Sept. 11 (highs in the lower to mid 90s).

The advisory covered three NWS zones: Orange County Coastal Areas, Orange County Inland Areas, and the Santa Ana Mountains and Foothills.

Infrastructure Impact

On Sept. 9, the City of Santa Ana reported traffic signals dark or flashing at Main Street and East MacArthur Boulevard and at Newhope Street and 1st Street due to power outages attributed to heat-related grid stress. Southern California Edison worked to restore power; the city asked drivers to treat the intersections as four-way stops.

Relief

Cooler air arrived on schedule. According to ABC7, a low-pressure system lingering over the region on Sept. 15 delivered the anticipated temperature relief, ending the multi-day heat episode.

▸ EVENT TIMELINE
7 moments
  1. Sep 7, 20:16(about 2 months ago)

    NWS San Diego issues a Heat Advisory for Orange County coastal and inland zones and the Santa Ana Mountains, effective 10 AM Tuesday Sept. 8 through 8 PM Thursday Sept. 10.

    WTHHeat Advisory — San Diego County Coastal Areas; Orange Coun…WTHHeat Advisory — Santa Ana Mountains and Foothills; Orange C…
  2. Sep 8, 06:52(about 2 months ago)

    6:52 a.m. Sept. 8: NWS San Diego upgrades Orange County coastal and inland zones to an Extreme Heat Warning through 8 p.m. Wednesday Sept. 9, with a Heat Advisory to follow through 8 p.m. Thursday Sept. 10.

    WTHExtreme Heat Warning — Orange County InlandWTHExtreme Heat Warning — San Diego County Coastal Areas; Oran…
  3. Sep 8, 10:00(about 2 months ago)

    Heat Advisory takes effect countywide at 10 AM Tuesday.

  4. Sep 9, 14:29(about 1 month ago)

    Santa Ana reports traffic signals dark at Main Street and MacArthur Boulevard and at Newhope Street and 1st Street because of power outages; SCE works to restore power.

    NEWSanta Ana: Traffic signals out Main and MacArthur, Newhope …
  5. Sep 9, 19:44(about 1 month ago)

    7:44 p.m. Sept. 9: NWS extends the Extreme Heat Warning through 8 p.m. Thursday Sept. 10 (inland highs 90 to 100; Major to Extreme HeatRisk).

    WTHExtreme Heat Warning — San Diego County Coastal Areas; Oran…WTHExtreme Heat Warning — Orange County Inland
  6. Sep 11, 12:50(about 1 month ago)

    12:50 p.m. Sept. 11: NWS issues a final Heat Advisory for Orange County inland areas until 8 p.m. Friday (highs in the lower to mid 90s); the Extreme Heat Warning has expired.

    WTHHeat Advisory — Orange County InlandNEWOC Register: Heat advisory active for Orange County until F…
  7. Sep 15, 08:01(about 1 month ago)

    ABC7 reports Southern California is getting relief from the heat as a low-pressure system lingers over the region.

    NEWABC7: Dry and warmer conditions expected to return to South…
▸ EVIDENCE
15 items
  1. NEWabout 12 hours ago
    ABC7: Dry and warmer conditions expected to return to Southern California Friday

    Dry and warmer conditions are expected to return to Southern California Friday and continue through the weekend, with a weak Santa Ana wind pattern developing.

  2. WTHabout 1 month ago
    Heat Advisory — Orange County Inland

    Heat Advisory issued September 11 at 12:50PM PDT until September 11 at 8:00PM PDT by NWS San Diego CA

  3. NEWabout 1 month ago
    OC Register: Heat advisory active for Orange County until Friday evening

    An updated heat advisory was issued by the National Weather Service on Friday at 12:50 p.m. in effect until 8 p.m. for Orange County.

  4. WTHabout 1 month ago
    Extreme Heat Warning — San Diego County Coastal Areas; Orange County Coastal

    Extreme Heat Warning issued September 10 at 12:32PM PDT until September 10 at 8:00PM PDT by NWS San Diego CA

  5. WTHabout 1 month ago
    Extreme Heat Warning — Orange County Inland

    Extreme Heat Warning issued September 10 at 12:32PM PDT until September 10 at 8:00PM PDT by NWS San Diego CA

  6. WTHabout 1 month ago
    Extreme Heat Warning — San Diego County Coastal Areas; Orange County Coastal

    Extreme Heat Warning issued September 9 at 7:44PM PDT until September 10 at 8:00PM PDT by NWS San Diego CA

  7. WTHabout 1 month ago
    Extreme Heat Warning — Orange County Inland

    Extreme Heat Warning issued September 9 at 7:44PM PDT until September 10 at 8:00PM PDT by NWS San Diego CA

  8. NEWabout 1 month ago
    Santa Ana: Traffic signals out Main and MacArthur, Newhope and 1st Street intersections due to power outages

    Traffic signals are currently out of service or flashing at the intersections of Main Street and E. MacArthur Boulevard and at Newhope and 1st Street due to power outages. Main and MacArthur intersection: SCE is working to repair equipment and restore power so that the City may turn the traffic sign

  9. WTHabout 1 month ago
    Extreme Heat Warning — Orange County Inland

    Extreme Heat Warning issued September 9 at 2:58AM PDT until September 9 at 8:00PM PDT by NWS San Diego CA

  10. WTHabout 2 months ago
    Extreme Heat Warning — Orange County Inland

    Extreme Heat Warning issued September 8 at 7:01AM PDT until September 9 at 8:00PM PDT by NWS San Diego CA

  11. WTHabout 2 months ago
    Extreme Heat Warning — San Diego County Coastal Areas; Orange County Coastal

    Extreme Heat Warning issued September 8 at 7:01AM PDT until September 9 at 8:00PM PDT by NWS San Diego CA

  12. WTHabout 2 months ago
    Heat Advisory — San Diego County Coastal Areas; Orange County Coastal

    Heat Advisory issued September 7 at 8:16PM PDT until September 10 at 8:00PM PDT by NWS San Diego CA

  13. WTHabout 2 months ago
    Heat Advisory — Santa Ana Mountains and Foothills; Orange County Inland

    Heat Advisory issued September 7 at 8:16PM PDT until September 10 at 8:00PM PDT by NWS San Diego CA

  14. NEWabout 2 months ago
    OC Register: Heat advisory issued for Santa Ana Mountains and Orange County from Tuesday to Thursday

    Santa Ana Mountains/Foothills and Orange County were placed under an updated heat advisory by the National Weather Service on Monday at 8:16 p.m. The advisory is valid from Tuesday 10 a.m. until Thursday Sept. 10, at 8 p.m.

  15. NEWabout 2 months ago
    OC Register: Heat advisory issued for Orange County Coast and San Diego County Coastal Areas from Tuesday to Thursday

    Orange County Coast and San Diego County Coastal Areas are the focus of an updated heat advisory issued at 8:16 p.m. on Monday by the National Weather Service. The advisory is valid from Tuesday 10 a.m. until Thursday Sept. 10, at 8 p.m.

▸ SOURCES
15 links