Wildfire smoke EPA monitor flag
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.
Why we think this happened
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. These overlapping impacts form one time-bounded Pacific Northwest occur
EPA monitor flag EPA attached an exceptional-event qualifier to the affected samples. The agency flagged the measurement itself; no separate agency record describes the event.
U.S. EPA Air Quality System and the submitting air monitoring agency · Oct 13, 2022 official
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.
U.S. EPA Air Quality System and the submitting air monitoring agency · Oct 15, 2022 official
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.
U.S. EPA Air Quality System and the submitting air monitoring agency · Oct 20, 2022 official
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.
See every retained source and limitation ↓
Sequence: Seattle (Oct 13) → Portland (Oct 19)
Evidence path
A cause is more convincing when the record connects three things: something happened, the air mass moved toward the region, and local instruments responded. Here is how much of that chain is documented for this event.
Source or mechanism
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…
View supporting source ↗Air-mass movement
Contemporaneous reporting says Oregon DEQ issued a Portland-metro advisory for smoke and smog, with wildfire smoke trapped near ground level by valley inversions.
View transport source ↗Local response
EPA monitors recorded the event across 2 metros. The peak daily concentration is roughly 11.6 cigarette-equivalents at the outdoor daily rate.
Inspect the pollutant and weather signals ↓Event autopsy
Before, during, and after the episode: nearby pollutant monitors and surface-weather stations show what changed. This context tests the “Wildfire smoke” explanation; it does not assign the cause by itself.
Seattle-Tacoma-Bellevue, WA
Monitor comparison window 2022-10-16 to 2022-10-23 · PM2.5 target: DARRINGTON - FIR ST (Darrington High School)
301% above nearby days
20% lower than surrounding days
253% higher than surrounding days
301% higher than surrounding days
253% higher than surrounding days
34% higher than surrounding days
65% higher than surrounding days
13% higher than surrounding days
About the same as surrounding days
About the same as surrounding days
20% lower than surrounding days
Portland-Vancouver-Hillsboro, OR-WA
Monitor comparison window 2022-10-16 to 2022-10-23 · PM2.5 target: Vancouver-NE 84th Ave
364% above nearby days
About the same as surrounding days
173% higher than surrounding days
364% higher than surrounding days
173% higher than surrounding days
156% higher than surrounding days
8% higher than surrounding days
23% higher than surrounding days
About the same as surrounding days
About the same as surrounding days
About the same as surrounding days
About the same as surrounding days
About the same as surrounding days
Source: U.S. EPA AirData daily observations and, where available, nearby ASOS/AWOS surface observations. Values are descriptive medians over the retained monitor set; missing measurements remain missing. Transport and source evidence remain separate layers because this instrument pattern does not assign a cause by itself.
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.
Views from the selected metro
Select a metro on the map to see nearby cameras. Where an operator archive reaches the event, drag the divider to compare two moments, adjust either date and time, or play the available event-day frames. Camera imagery is visual context, not an air-quality measurement or proof of smoke.
No useful public camera views are currently available within 80 km of this metro.
| 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.
Public evidence library
Each card states what a source supports—and what it does not. Official records, research, reporting, community observations, and transparent inferences remain visibly different kinds of evidence.
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.
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.
EPA monitor flag EPA attached an exceptional-event qualifier to the affected samples. The agency flagged the measurement itself; no separate agency record describes the event.
This episode was grouped from the monitor record by the catalog pipeline and given its cause from the evidence listed above. It has not been individually reviewed and signed off, so its boundaries, cause, and name may change as evidence accumulates. Grouping policy common_sense_root_cause_grouping.v2. The cause label reflects the assembled evidence above, not an IAQng detection formula. If it is wrong, tell us.