Wildfire smoke
Wildfire Smoke episode, 2017-09-04 through 2017-09-08
Daily PM2.5 peaked at 194.9 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 ≈ 35.5 cigarettes. Across everyone living in the affected metros, that is the collective equivalent of ≈ 21 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 | 194.9 µg/m³ | 37.2 | Sep 7, 2017 | #6 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, CALIFORNIA, Sep 7, 2017 "Scattered monsoon thunderstorms developed across the northern Baja California mountains as well as far northwest Mexico, during the late afternoon hours on September 7th and they generated very strong and gusty outflow …" record →
- NOAA Storm Events Dust Storm, CALIFORNIA, Sep 3, 2017 "A northwest surge of tropical moisture during the Labor Day weekend produced strong thunderstorms over the Kern County Mountains during the late afternoon of September 3. These thunderstorms produced heavy rain which cau…" record →
- NOAA Storm Events Dust Storm, CALIFORNIA, Sep 3, 2017 "A northwest surge of tropical moisture during the Labor Day weekend produced strong thunderstorms over the Kern County Mountains during the late afternoon of September 3. These thunderstorms produced heavy rain which cau…" record →
- NOAA Storm Events Dust Storm, CALIFORNIA, Sep 3, 2017 "A northwest surge of tropical moisture during the Labor Day weekend produced strong thunderstorms over the Kern County Mountains during the late afternoon of September 3. These thunderstorms produced heavy rain which cau…" record →
- NOAA Storm Events Dust Storm, CALIFORNIA, Sep 3, 2017 "A northwest surge of tropical moisture during the Labor Day weekend produced strong thunderstorms over the Kern County Mountains during the late afternoon of September 3. These thunderstorms produced heavy rain which cau…" record →
- NOAA Storm Events Dust Storm, CALIFORNIA, Sep 3, 2017 "A northwest surge of tropical moisture during the Labor Day weekend produced strong thunderstorms over the Kern County Mountains during the late afternoon of September 3. These thunderstorms produced heavy rain which cau…" record →
- NOAA Storm Events Dust Storm, CALIFORNIA, Sep 3, 2017 "A northwest surge of tropical moisture during the Labor Day weekend produced strong thunderstorms over the Kern County Mountains during the late afternoon of September 3. These thunderstorms produced heavy rain which cau…" record →
- NOAA Storm Events Dust Storm, CALIFORNIA, Sep 3, 2017 "A northwest surge of tropical moisture during the Labor Day weekend produced strong thunderstorms over the Kern County Mountains during the late afternoon of September 3. These thunderstorms produced heavy rain which cau…" record →
- NOAA Storm Events Dust Storm, CALIFORNIA, Sep 3, 2017 "A northwest surge of tropical moisture during the Labor Day weekend produced strong thunderstorms over the Kern County Mountains during the late afternoon of September 3. These thunderstorms produced heavy rain which cau…" record →
- NOAA Storm Events Dust Storm, CALIFORNIA, Sep 3, 2017 "A northwest surge of tropical moisture during the Labor Day weekend produced strong thunderstorms over the Kern County Mountains during the late afternoon of September 3. These thunderstorms produced heavy rain which cau…" record →
- NOAA Storm Events Dense Smoke, WASHINGTON, Sep 4, 2017 "Smoke from numerous regional wildfires in Canada, Montana, Oregon and Washington fumigated eastern Washington from September 4th through the 8th. Air Quality sensors throughout eastern Washington recorded Unhealthy and V…" record →
- NOAA Storm Events Dense Smoke, WASHINGTON, Sep 4, 2017 "Smoke from numerous regional wildfires in Canada, Montana, Oregon and Washington fumigated eastern Washington from September 4th through the 8th. Air Quality sensors throughout eastern Washington recorded Unhealthy and V…" record →
EPA AQS monitor qualifier 5
- 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 2017-09-07, 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 2017-09-08, 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 2017-09-06, 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 2017-09-04, 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 2017-09-05, 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 2017-09-04T17:13Z, explicitly identifies wildfire smoke. IEM is the archive, not the official system of record.
Agency and publisher pages 1
- Air Quality Report - September 2017 The regional clean-air agency attributed the September 4–8 episode to heavy smoke transported from wildfires in Montana and British Columbia; a subsidence inversion restricted dispersion. It reports PM2.5 reached 205.5 µg/m³ on September 7.
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.