Wildfire smoke
2025-01-22 wildfire smoke episode affecting Oxnard-Thousand Oaks-Ventura, CA
Named source Hughes Fire 10,425 acres , CA · IRWIN 2025-CAANF-250270
Daily PM2.5 peaked at 45.3 µg/m³ near Oxnard across 1 covered metro home to 835,427 people.
Counting the extra PM2.5 above each metro's typical day, this event handed the average affected resident ≈ 1.6 cigarettes. Across everyone living in the affected metros, that is the collective equivalent of ≈ 1.3 million cigarettes. An awareness illustration of outdoor exposure at 22 µg/m³ per cigarette (Berkeley Earth), counting only the event's ranked days; not a medical dose.
Episode peak
-- cigarettes
The smoke map's scale, replayed over this event: the surface interpolates between covered metros' daily records, framed to the affected region. Hover for a reading, click a metro to pin it to the card. Days a monitor did not report draw nothing.
What happened, in the record
The supplied retained evidence supports wildfire smoke for this event; no supplied evidence establishes membership in a broader time-bounded episode.
Affected metros
| Metro | Peak PM2.5 | Cigarettes, whole event | Peak day | All-time standing |
|---|---|---|---|---|
| Oxnard-Thousand Oaks-Ventura, CA | 45.3 µg/m³ | 2.1 | Jan 22, 2025 | #11 of its top days |
"Cigarettes, whole event" totals a metro's ranked event days at 22 µg/m³ per cigarette: what a person outdoors there breathed across the event, as the illustration. "All-time standing" is where this episode's days sit in each metro's ranked record (worst-area measure, since 1999). Full local context is on each metro's Air Records page.
The evidence
EPA AQS monitor qualifier 1
- AQS PM2.5 qualifier IT — Wildfire-U. S. EPA AQS carries an agency-submitted informational qualifier (IT, Wildfire-U. S.) on 30 PM2.5 samples in the candidate CBSA on 2025-01-22, identifying wildfire smoke as affecting the samples. An informational qualifier is an official submitting-agency flag, not a request for exclusion or an EPA-concurred determination.
NWS Air Quality Alert 1
- Archived Ventura County Air Quality Alert, January 22, 2025 Ventura County APCD explicitly attributed increased particulate matter in Oxnard and nearby communities to wildfire smoke. IEM is the archive, not the official system of record.
Agency and publisher pages 2
- Air Quality Alert for smoke issued in county The district stated that smoke from the Hughes Fire made the AQI unhealthy in Oxnard and other Ventura County communities and identified PM2.5 as the relevant fine-particle pollutant.
- Wildfire Smoke Alert: Cal/OSHA urges employers to protect workers from unhealthy air in Ventura and Los Angeles Counties State labor officials reported wildfire smoke affecting Oxnard and directed employers to monitor PM2.5 AQI.
Cited authorities: Ventura County Air Pollution Control District
Status and provenance
Research preview: this record carries research-only status and its boundaries, cause, and name may change as evidence review completes. Grouping policy common_sense_root_cause_grouping.v2. The cause label reflects the assembled evidence above, not an IAQng detection formula.