Wildfire smoke
2021-08-13 Spokane-Spokane Valley wildfire-smoke episode
Daily PM2.5 peaked at 123.7 µg/m³ near Spokane across 1 covered metro home to 604,962 people.
Counting the extra PM2.5 above each metro's typical day, this event handed the average affected resident ≈ 10.1 cigarettes. Across everyone living in the affected metros, that is the collective equivalent of ≈ 6.1 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
Supplied qualified evidence supports wildfire-smoke as the root cause. The grouping includes only events linked by explicit shared episode evidence; otherwise this remains a single-event episode.
Affected metros
| Metro | Peak PM2.5 | Cigarettes, whole event | Peak day | All-time standing |
|---|---|---|---|---|
| Spokane-Spokane Valley, WA | 123.7 µg/m³ | 10.7 | Aug 13, 2021 | #17 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
Official records
- NOAA Storm Events Dust Storm, ARIZONA, Aug 13, 2021 "A classic bow echo developed along the Mogollon Rim in central Arizona around 1900MST on the 13th and merged with thunderstorm clusters that developed in south-central Arizona around 2030MST to form one southwestward-mov…" record →
- NOAA Storm Events Dust Storm, ARIZONA, Aug 14, 2021 "A classic bow echo developed along the Mogollon Rim in central Arizona around 1900MST on the 13th and merged with thunderstorm clusters that developed in south-central Arizona around 2030MST to form one southwestward-mov…" record →
EPA AQS monitor qualifier 2
- AQS PM2.5 qualifier IT — Wildfire-U. S. EPA AQS carries an agency-submitted informational qualifier (IT, Wildfire-U. S.) on 144 PM2.5 samples in the candidate CBSA on 2021-08-13, 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 144 PM2.5 samples in the candidate CBSA on 2021-08-14, 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 1
- Spokane County Air Quality: Dates when PM2.5 failed to meet the health-based standard The agency's historical PM2.5 event table identifies August 13 and August 14, 2021 in Spokane County as wildfire-smoke days.
What remains uncertain
- An AQS informational qualifier is an official submitting-agency flag, not an EPA-concurred exclusion determination.
- The supplied evidence resolves cause but does not establish identity with another candidate episode.
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.