Wildfire smoke
October 12-20, 2022 Pacific Northwest wildfire-smoke episode
Named source Nakia Creek Fire 1,918 acres , WA · IRWIN 2022-WAPCS-000220
Daily PM2.5 peaked at 255.9 µg/m³ near Seattle across 2 covered metros home to 6.7 million people. 1 metro recorded their worst day on record; 2 placed a top-ten day.
Counting the extra PM2.5 above each metro's typical day, this event handed the average affected resident ≈ 17.7 cigarettes. Across everyone living in the affected metros, that is the collective equivalent of ≈ 118 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
Agency evidence identifies October 12-20 as a wildfire-smoke impact window in the Seattle area, and the later regional event extends through Portland with identified Washington fire sources. These overlapping impacts form one time-bounded Pacific Northwest occurrence. Agency evidence identifies October 12-20 as a wildfire-smoke impact window in the Seattle area, and the later regional event extends through Portland with identified Washington fire sources. These overlapping impacts form one time-bounded Pacific Northwest occurrence. Agency evidence identifies October 12-20 as a wildfire-smoke impact window in the Seattle area, and the later regional event extends through Portland with identified Washington fire sources. These overlapping impacts form one time-bounded Pacific Northwest occur
Sequence: Seattle (Oct 19) → Portland (Oct 19)
Affected metros
| Metro | Peak PM2.5 | Cigarettes, whole event | Peak day | All-time standing |
|---|---|---|---|---|
| Seattle-Tacoma-Bellevue, WA | 255.9 µg/m³ | 26.2 | Oct 19, 2022 | Worst day on record |
| Portland-Vancouver-Hillsboro, OR-WA | 81.3 µg/m³ | 7.1 | Oct 19, 2022 | #10 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 6
- AQS PM2.5 qualifier IT — Wildfire-U. S. EPA AQS carries an agency-submitted informational qualifier (IT, Wildfire-U. S.) on 240 PM2.5 samples in the candidate CBSA on 2022-10-13, 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.
- AQS PM2.5 qualifier IT — Wildfire-U. S. EPA AQS carries an agency-submitted informational qualifier (IT, Wildfire-U. S.) on 240 PM2.5 samples in the candidate CBSA on 2022-10-15, 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.
- AQS PM2.5 qualifier IT — Wildfire-U. S. EPA AQS carries an agency-submitted informational qualifier (IT, Wildfire-U. S.) on 240 PM2.5 samples in the candidate CBSA on 2022-10-20, 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.
- AQS PM2.5 qualifier IT — Wildfire-U. S. EPA AQS carries an agency-submitted informational qualifier (IT, Wildfire-U. S.) on 238 PM2.5 samples in the candidate CBSA on 2022-10-19, 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.
- AQS PM2.5 qualifier IT — Wildfire-U. S. EPA AQS carries an agency-submitted informational qualifier (IT, Wildfire-U. S.) on 24 PM2.5 samples in the candidate CBSA on 2022-10-19, 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.
- AQS PM2.5 qualifier IT — Wildfire-U. S. EPA AQS carries an agency-submitted informational qualifier (IT, Wildfire-U. S.) on 28 PM2.5 samples in the candidate CBSA on 2022-10-20, 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.
Agency and publisher pages 5
- 2022 Data Summary The agency identifies October 12–20, 2022 as wildfire-smoke-impacted days at all monitoring sites in its jurisdiction.
- Where There's Smoke There's Fire King County warned of wildfire smoke on October 19 and directed residents to incident information for the Bolt Creek and Loch Katrine fires.
- Wildfire smoke continues to burden communities across Oregon, DEQ report shows Oregon DEQ’s 2022 season assessment attributes October Portland-metro smoke impacts to the Nakia Creek Fire in Clark County, Washington.
- Smoke returns to Seattle area, expected to linger through weekend Contemporaneous reporting, citing the Washington Smoke blog and state health officials, describes wildfire smoke returning to Seattle while fires remained active in Cascade mountain valleys.
- ‘Unhealthy’ air advisory issued for Portland area until Friday Contemporaneous reporting says Oregon DEQ issued a Portland-metro advisory for smoke and smog, with wildfire smoke trapped near ground level by valley inversions.
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.