Wildfire smoke
2023 early-September Canadian wildfire-smoke episode
Daily PM2.5 peaked at 63.4 µg/m³ near Wichita across 4 covered metros home to 4.7 million people. 3 metros 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 ≈ 3.3 cigarettes. Across everyone living in the affected metros, that is the collective equivalent of ≈ 15 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 supplied evidence supports wildfire smoke for this event. It is grouped with 1 other supplied event because the evidence identifies Canada as the shared origin and the affected intervals form one continuous 2023-09-06 through 2023-09-07 occurrence. Qualified supplied evidence supports wildfire smoke for this event. It is grouped with 1 other supplied event because the evidence identifies Canada as the shared origin and the affected intervals form one continuous 2023-09-06 through 2023-09-07 occurrence.
Sequence: Wichita (Sep 6) → Kansas City (Sep 6) → Omaha (Sep 6) → Des Moines (Sep 6)
Affected metros
| Metro | Peak PM2.5 | Cigarettes, whole event | Peak day | All-time standing |
|---|---|---|---|---|
| Wichita, KS | 63.4 µg/m³ | 5.1 | Sep 6, 2023 | #2 of its top days |
| Kansas City, MO-KS | 60.8 µg/m³ | 5.0 | Sep 7, 2023 | #5 of its top days |
| Omaha-Council Bluffs, NE-IA | 59.8 µg/m³ | 2.7 | Sep 6, 2023 | #4 of its top days |
| Des Moines-West Des Moines, IA | 37.1 µg/m³ | 1.7 | Sep 6, 2023 | #25 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 IF — Fire - Canadian. EPA AQS carries an agency-submitted informational qualifier (IF, Fire - Canadian.) on 96 PM2.5 samples in the candidate CBSA on 2023-09-06, 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 IF — Fire - Canadian. EPA AQS carries an agency-submitted informational qualifier (IF, Fire - Canadian.) on 96 PM2.5 samples in the candidate CBSA on 2023-09-07, 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 IF — Fire - Canadian. EPA AQS carries an agency-submitted informational qualifier (IF, Fire - Canadian.) on 74 PM2.5 samples in the candidate CBSA on 2023-09-06, 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 IF — Fire - Canadian. EPA AQS carries an agency-submitted informational qualifier (IF, Fire - Canadian.) on 46 PM2.5 samples in the candidate CBSA on 2023-09-07, 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 IF — Fire - Canadian. EPA AQS carries an agency-submitted informational qualifier (IF, Fire - Canadian.) on 72 PM2.5 samples in the candidate CBSA on 2023-09-07, 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 IF — Fire - Canadian. EPA AQS carries an agency-submitted informational qualifier (IF, Fire - Canadian.) on 47 PM2.5 samples in the candidate CBSA on 2023-09-06, 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.
NWS Air Quality Alert 1
- Archived Iowa Air Quality Alert, September 6, 2023 Iowa DNR explicitly attributed elevated fine-particle levels in the Des Moines portion of the regional event to Canadian wildfire smoke. IEM is the archive, not the official system of record.
Agency and publisher pages 5
- Wichita sees poor air quality for second day. See the forecast Contemporaneous reporting cited a meteorological explanation that the Wichita haze was coming from fires in Canada.
- ‘Unhealthy’ haze lingers over Wichita Local reporting documented visible and odorous smoke and unhealthy conditions in Wichita on the event date.
- Unhealthy air detected in parts of the state from Canadian wildfire smoke Contemporaneous Iowa reporting identified Canadian wildfire smoke as affecting air quality around Des Moines.
- Canadian wildfires worsen air quality, prompt smoke advisory in Omaha metro Omaha reporting identified haze imported from northern Canadian, including Northwest Territories, wildfires after a cold-front wind shift.
- Smoke plumes from Canadian wildfires making KC’s skies hazy Satellite imagery and the regional air-quality alert were reported as showing wildfire smoke from western Canada in Kansas City skies.
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.