Wildfire smoke Agency determination
Daily PM2.5 peaked at 53.5 µg/m³ near Kansas City across 6 covered metros home to 7.2 million people. 4 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 ≈ 3.1 cigarettes. Across everyone living in the affected metros, that is the collective equivalent of ≈ 22 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
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.
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 · Aug 2, 2021 official
EPA AQS carries an agency-submitted informational qualifier (IF, Fire - Canadian.) on 52 PM2.5 samples in the candidate CBSA on 2021-08-02, 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 · Aug 1, 2021 official
EPA AQS carries an agency-submitted informational qualifier (IT, Wildfire-U. S.) on 40 PM2.5 samples in the candidate CBSA on 2021-08-01, 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 · Aug 2, 2021 official
EPA AQS carries an agency-submitted informational qualifier (IT, Wildfire-U. S.) on 48 PM2.5 samples in the candidate CBSA on 2021-08-02, 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: Kansas City (Aug 1) → Wichita (Aug 1) → Omaha (Aug 1) → Des Moines (Aug 1) → Oklahoma City (Aug 2) → Tulsa (Aug 2)
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 52 PM2.5 samples in the candidate CBSA on 2021-08-02, identifying wildfire smoke as affecting the samples. An informational qualifier is an official…
View supporting source ↗Air-mass movement
The retained record does not yet show how air traveled from the proposed source to these metros. A trajectory replay or dated plume analysis belongs here.
Local response
EPA monitors recorded the event across 6 metros. The peak daily concentration is roughly 2.4 cigarette-equivalents at the outdoor daily rate.
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.
Des Moines-West Des Moines, IA
Monitor comparison window 2021-07-29 to 2021-08-05 · PM2.5 target: CARPENTER
44% above nearby days
14% lower than surrounding days
11% lower than surrounding days
44% higher than surrounding days
11% lower than surrounding days
19% higher than surrounding days
14% lower than surrounding days
About the same as surrounding days
About the same as surrounding days
14% lower than surrounding days
Kansas City, MO-KS
Monitor comparison window 2021-07-29 to 2021-08-05 · PM2.5 target: Troost
147% above nearby days
15% higher than surrounding days
43% higher than surrounding days
147% higher than surrounding days
43% higher than surrounding days
12% higher than surrounding days
29% lower than surrounding days
About the same as surrounding days
14% lower than surrounding days
About the same as surrounding days
About the same as surrounding days
About the same as surrounding days
15% higher than surrounding days
Omaha-Council Bluffs, NE-IA
Monitor comparison window 2021-07-29 to 2021-08-05 · PM2.5 target: 4102 Woolworth Ave. on Healthcenter Warehouse
49% above nearby days
30% lower than surrounding days
12% higher than surrounding days
49% higher than surrounding days
12% higher than surrounding days
10% higher than surrounding days
35% higher than surrounding days
31% lower than surrounding days
12% lower than surrounding days
About the same as surrounding days
About the same as surrounding days
30% lower than surrounding days
Wichita, KS
Monitor comparison window 2021-07-29 to 2021-08-06 · PM2.5 target: WICHITA HD
82% above nearby days
12% lower than surrounding days
42% higher than surrounding days
82% higher than surrounding days
42% higher than surrounding days
7% lower than surrounding days
About the same as surrounding days
17% lower than surrounding days
About the same as surrounding days
7% lower than surrounding days
12% lower than surrounding days
Oklahoma City, OK
Monitor comparison window 2021-07-29 to 2021-08-06 · PM2.5 target: OKC Near Road
99% above nearby days
12% higher than surrounding days
38% higher than surrounding days
99% higher than surrounding days
38% higher than surrounding days
About the same as surrounding days
28% lower than surrounding days
Adjacent observations available
About the same as surrounding days
About the same as surrounding days
About the same as surrounding days
12% higher than surrounding days
Tulsa, OK
Monitor comparison window 2021-07-29 to 2021-08-06 · PM2.5 target: TULSA CENTRAL
47% above nearby days
39% higher than surrounding days
41% higher than surrounding days
47% higher than surrounding days
41% higher than surrounding days
About the same as surrounding days
41% lower than surrounding days
Adjacent observations available
About the same as surrounding days
About the same as surrounding days
About the same as surrounding days
39% higher 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 |
|---|---|---|---|---|
| Kansas City, MO-KS | 53.5 µg/m³ | 4.5 | Aug 1, 2021 | #7 of its top days |
| Wichita, KS | 51.7 µg/m³ | 6.5 | Aug 2, 2021 | #4 of its top days |
| Oklahoma City, OK | 50.5 µg/m³ | 4.2 | Aug 2, 2021 | #2 of its top days |
| Tulsa, OK | 50.3 µg/m³ | 4.0 | Aug 2, 2021 | #4 of its top days |
| Omaha-Council Bluffs, NE-IA | 39.7 µg/m³ | 1.8 | Aug 1, 2021 | #24 of its top days |
| Des Moines-West Des Moines, IA | 39.2 µg/m³ | 1.8 | Aug 1, 2021 | #22 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 52 PM2.5 samples in the candidate CBSA on 2021-08-02, 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 40 PM2.5 samples in the candidate CBSA on 2021-08-01, 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 48 PM2.5 samples in the candidate CBSA on 2021-08-02, 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 48 PM2.5 samples in the candidate CBSA on 2021-08-01, 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 96 PM2.5 samples in the candidate CBSA on 2021-08-03, 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 96 PM2.5 samples in the candidate CBSA on 2021-08-02, 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 88 PM2.5 samples in the candidate CBSA on 2021-08-01, 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.
An archived NWS Air Quality Alert for Kansas City, MO-KS, issued 2021-08-02T16:40Z, explicitly identifies wildfire smoke. IEM is the archive, not the official system of record.
Canadian wildfires' smoke causing air quality issues in Iowa
The supplied wire-story title explicitly attributes Iowa air-quality problems during the event window to Canadian wildfire smoke; the page could not be retrieved.
Wildfire smoke continues to affect Wichita air quality
The contemporaneous local title explicitly states that wildfire smoke affected Wichita air quality; full text was unavailable.
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.