Wildfire smoke Agency determination
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.
Why we think this happened
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.
Agency determination A government body issued a record naming this cause for this event: an NWS air-quality alert, a NOAA Storm Events record, or a state or local official archive.
U.S. EPA Air Quality System and the submitting air monitoring agency · Sep 6, 2023 official
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.
U.S. EPA Air Quality System and the submitting air monitoring agency · Sep 7, 2023 official
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.
U.S. EPA Air Quality System and the submitting air monitoring agency · Sep 6, 2023 official
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.
See every retained source and limitation ↓
Sequence: Wichita (Sep 6) → Kansas City (Sep 6) → Omaha (Sep 6) → Des Moines (Sep 6)
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 (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…
View supporting source ↗Air-mass movement
Contemporaneous reporting cited a meteorological explanation that the Wichita haze was coming from fires in Canada.
View transport source ↗Local response
Local reporting documented visible and odorous smoke and unhealthy conditions in Wichita on the event date.
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.
Wichita, KS
Monitor comparison window 2023-09-03 to 2023-09-10 · PM2.5 target: WICHITA HD
242% above nearby days
5% lower than surrounding days
117% higher than surrounding days
242% higher than surrounding days
117% higher than surrounding days
47% higher than surrounding days
25% lower than surrounding days
7% higher than surrounding days
6% lower than surrounding days
About the same as surrounding days
5% lower than surrounding days
Des Moines-West Des Moines, IA
Monitor comparison window 2023-09-03 to 2023-09-10 · PM2.5 target: PUBLIC WORKS, DES MOINES IA, FRM, SEQ. SAMPLER, SPM, ROOF
151% above nearby days
About the same as surrounding days
39% higher than surrounding days
151% higher than surrounding days
39% higher than surrounding days
24% lower than surrounding days
14% higher than surrounding days
7% lower than surrounding days
About the same as surrounding days
Kansas City, MO-KS
Monitor comparison window 2023-09-03 to 2023-09-10 · PM2.5 target: Troost
267% above nearby days
12% lower than surrounding days
107% higher than surrounding days
267% higher than surrounding days
107% higher than surrounding days
42% higher than surrounding days
26% higher than surrounding days
11% lower than surrounding days
About the same as surrounding days
About the same as surrounding days
About the same as surrounding days
12% lower than surrounding days
Omaha-Council Bluffs, NE-IA
Monitor comparison window 2023-09-03 to 2023-09-10 · PM2.5 target: ON ROOF OF GOOD SHEPARD LUTHERAN HOME
240% above nearby days
19% lower than surrounding days
121% higher than surrounding days
240% higher than surrounding days
121% higher than surrounding days
32% higher than surrounding days
398% higher than surrounding days
7% lower than surrounding days
About the same as surrounding days
About the same as surrounding days
8% lower than surrounding days
19% lower than 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 |
|---|---|---|---|---|
| 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.
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 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.
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.
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.
Agency determination A government body issued a record naming this cause for this event: an NWS air-quality alert, a NOAA Storm Events record, or a state or local official archive.
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.