Wildfire smoke
Wildfire-smoke episode, 2018-08-19 through 2018-08-20
Daily PM2.5 peaked at 185 µg/m³ near Spokane across 1 covered metro home to 604,962 people. 1 metro placed a top-ten day in their record.
Counting the extra PM2.5 above each metro's typical day, this event handed the average affected resident ≈ 14.6 cigarettes. Across everyone living in the affected metros, that is the collective equivalent of ≈ 8.8 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
Qualified frozen evidence supports wildfire smoke as the broad cause for this time-bounded episode.
Affected metros
| Metro | Peak PM2.5 | Cigarettes, whole event | Peak day | All-time standing |
|---|---|---|---|---|
| Spokane-Spokane Valley, WA | 185 µg/m³ | 15.2 | Aug 19, 2018 | #9 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 Dense Smoke, WASHINGTON, Aug 3, 2018 "Multiple large wildfires in the Cascades and the mountains of northeast Washington produced copious quantities of dense smoke through much of the month of August. The Methow Valley in particular was bracketed by two larg…" record →
- NOAA Storm Events Dense Smoke, WASHINGTON, Aug 16, 2018 "During the month of August numerous large wildfires in north Idaho, northeast Washington, Montana and British Columbia contributed to periods of Unhealthy and occasionally Hazardous air quality conditions in the Columbia…" record →
EPA AQS monitor qualifier 2
- AQS PM2.5 qualifier IF — Fire - Canadian. EPA AQS carries an agency-submitted informational qualifier (IF, Fire - Canadian.) on 24 PM2.5 samples in the candidate CBSA on 2018-08-19, 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 IF — Fire - Canadian. EPA AQS carries an agency-submitted informational qualifier (IF, Fire - Canadian.) on 24 PM2.5 samples in the candidate CBSA on 2018-08-20, 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.
NWS Air Quality Alert 1
- Air Quality Alert AQAOTX An archived NWS Air Quality Alert for Spokane-Spokane Valley, WA, issued 2018-08-19T19:43Z, explicitly identifies wildfire smoke. IEM is the archive, not the official system of record.
Agency and publisher pages 1
- Air Quality Report: August 2018 The regional air agency attributes widespread and heavy August 2018 smoke to wildfires in British Columbia, Washington, Oregon, Idaho, Montana, and California.
What remains uncertain
- AQS qualifiers are submitting-agency causal flags and do not by themselves establish EPA concurrence.
- The evidence resolves the broad cause but does not require a named fire, facility, or incident.
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.