Wildfire smoke Agency determination
Daily PM2.5 peaked at 67.2 µg/m³ near Des Moines across 18 covered metros home to 32 million people. 10 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 ≈ 2.2 cigarettes. Across everyone living in the affected metros, that is the collective equivalent of ≈ 70 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 8 other supplied events because the evidence identifies Canada as the shared origin and the affected intervals form one continuous 2023-07-15 through 2023-07-18 occurrence. Qualified supplied e
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 · Jul 15, 2023 official
EPA AQS carries an agency-submitted informational qualifier (IT, Wildfire-U. S.) on 320 PM2.5 samples in the candidate CBSA on 2023-07-15, 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 · Jul 16, 2023 official
EPA AQS carries an agency-submitted informational qualifier (IF, Fire - Canadian.) on 408 PM2.5 samples in the candidate CBSA on 2023-07-16, 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 · Jul 17, 2023 official
EPA AQS carries an agency-submitted informational qualifier (IF, Fire - Canadian.) on 193 PM2.5 samples in the candidate CBSA on 2023-07-17, 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: Des Moines (Jul 15) → Minneapolis (Jul 15) → Chicago (Jul 16) → Cleveland (Jul 17) → Columbus (Jul 17) → Akron (Jul 17) → Knoxville (Jul 17) → Winston (Jul 17) → Chattanooga (Jul 17) → Rochester (Jul 17) → +8 more metros
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 (IT, Wildfire-U. S.) on 320 PM2.5 samples in the candidate CBSA on 2023-07-15, identifying wildfire smoke as affecting the samples. An informational qualifier is an official…
View supporting source ↗Air-mass movement
Ohio EPA describes Canadian wildfire smoke moving into the Ohio Valley and building at the surface across northern Ohio on July 16–17.
View transport source ↗Local response
EPA monitors recorded the event across 18 metros. The peak daily concentration is roughly 3.1 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 2023-07-12 to 2023-07-19 · PM2.5 target: PUBLIC WORKS, DES MOINES IA, FRM, SEQ. SAMPLER, SPM, ROOF
526% above nearby days
About the same as surrounding days
526% higher than surrounding days
14% lower than surrounding days
14% higher than surrounding days
About the same as surrounding days
About the same as surrounding days
About the same as surrounding days
Akron, OH
Monitor comparison window 2023-07-14 to 2023-07-20 · PM2.5 target: Five Points
509% above nearby days
288% higher than surrounding days
509% higher than surrounding days
288% higher than surrounding days
100% lower than surrounding days
15% higher than surrounding days
Cleveland-Elyria, OH
Monitor comparison window 2023-07-14 to 2023-07-20 · PM2.5 target: GT Craig NCore PAMS
458% above nearby days
About the same as surrounding days
144% higher than surrounding days
458% higher than surrounding days
144% higher than surrounding days
56% higher than surrounding days
About the same as surrounding days
100% lower than surrounding days
About the same as surrounding days
About the same as surrounding days
About the same as surrounding days
About the same as surrounding days
About the same as surrounding days
Columbus, OH
Monitor comparison window 2023-07-14 to 2023-07-20 · PM2.5 target: Maple Canyon
222% above nearby days
113% higher than surrounding days
222% higher than surrounding days
113% higher than surrounding days
106% higher than surrounding days
7% higher than surrounding days
100% lower than surrounding days
12% higher than surrounding days
Chicago-Naperville-Elgin, IL-IN-WI
Monitor comparison window 2023-07-13 to 2023-07-19 · PM2.5 target: COM ED TRAINING CENTER
518% above nearby days
21% higher than surrounding days
169% higher than surrounding days
518% higher than surrounding days
169% higher than surrounding days
43% higher than surrounding days
About the same as surrounding days
9% 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
21% higher than surrounding days
Chattanooga, TN-GA
Monitor comparison window 2023-07-14 to 2023-07-20
494% above nearby days
494% higher than surrounding days
37% higher than surrounding days
About the same as surrounding days
Knoxville, TN
Monitor comparison window 2023-07-14 to 2023-07-20 · PM2.5 target: Spring Hill Elementary School
434% above nearby days
21% lower than surrounding days
240% higher than surrounding days
434% higher than surrounding days
240% higher than surrounding days
134% higher than surrounding days
About the same as surrounding days
Adjacent observations available
56% higher than surrounding days
14% lower than surrounding days
About the same as surrounding days
21% lower than surrounding days
Charlotte-Concord-Gastonia, NC-SC
Monitor comparison window 2023-07-14 to 2023-07-21 · PM2.5 target: Remount
477% above nearby days
About the same as surrounding days
340% higher than surrounding days
477% higher than surrounding days
340% higher than surrounding days
115% higher than surrounding days
57% higher than surrounding days
78% higher than surrounding days
26% higher than surrounding days
About the same as surrounding days
About the same as surrounding days
About the same as surrounding days
About the same as surrounding days
Greensboro-High Point, NC
Monitor comparison window 2023-07-14 to 2023-07-21 · PM2.5 target: Mendenhall School
352% above nearby days
353% higher than surrounding days
352% higher than surrounding days
353% higher than surrounding days
101% higher than surrounding days
19% higher than surrounding days
Greenville-Anderson-Mauldin, SC
Monitor comparison window 2023-07-14 to 2023-07-21 · PM2.5 target: Greenville ESC
290% above nearby days
273% higher than surrounding days
290% higher than surrounding days
273% higher than surrounding days
45% higher than surrounding days
95% higher than surrounding days
31% higher than surrounding days
About the same as surrounding days
Winston-Salem, NC
Monitor comparison window 2023-07-14 to 2023-07-21 · PM2.5 target: Hattie Avenue
483% above nearby days
268% higher than surrounding days
483% higher than surrounding days
268% higher than surrounding days
50% higher than surrounding days
17% lower than surrounding days
29% higher than surrounding days
9% lower than surrounding days
About the same as surrounding days
About the same as surrounding days
Columbia, SC
Monitor comparison window 2023-07-14 to 2023-07-21 · PM2.5 target: PARKLANE
196% above nearby days
59% lower than surrounding days
96% higher than surrounding days
196% higher than surrounding days
96% higher than surrounding days
218% higher than surrounding days
6% lower than surrounding days
110% higher than surrounding days
13% higher than surrounding days
About the same as surrounding days
About the same as surrounding days
59% lower than surrounding days
Minneapolis-St. Paul-Bloomington, MN-WI
Monitor comparison window 2023-07-12 to 2023-07-18 · PM2.5 target: Apple Valley
495% above nearby days
7% higher than surrounding days
130% higher than surrounding days
495% higher than surrounding days
130% higher than surrounding days
44% higher than surrounding days
35% lower than surrounding days
10% higher than surrounding days
5% lower than surrounding days
About the same as surrounding days
7% higher than surrounding days
Rochester, NY
Monitor comparison window 2023-07-14 to 2023-07-20 · PM2.5 target: ROCHESTER 2
675% above nearby days
73% higher than surrounding days
No adjacent-day comparison
675% higher than surrounding days
No adjacent-day comparison
55% higher than surrounding days
About the same as surrounding days
28% higher than surrounding days
12% higher than surrounding days
11% lower than surrounding days
About the same as surrounding days
7% higher than surrounding days
73% higher than surrounding days
Syracuse, NY
Monitor comparison window 2023-07-14 to 2023-07-20 · PM2.5 target: EAST SYRACUSE
550% above nearby days
33% higher than surrounding days
550% higher than surrounding days
10% higher than surrounding days
About the same as surrounding days
33% higher than surrounding days
Dayton, OH
Monitor comparison window 2023-07-14 to 2023-07-20 · PM2.5 target: Sinclair
162% above nearby days
70% higher than surrounding days
135% higher than surrounding days
162% higher than surrounding days
135% higher than surrounding days
57% higher than surrounding days
About the same as surrounding days
12% higher than surrounding days
About the same as surrounding days
About the same as surrounding days
About the same as surrounding days
70% higher than surrounding days
Durham-Chapel Hill, NC
Monitor comparison window 2023-07-15 to 2023-07-21 · PM2.5 target: Durham Armory
469% above nearby days
320% higher than surrounding days
469% higher than surrounding days
320% higher than surrounding days
About the same as surrounding days
45% higher than surrounding days
About the same as surrounding days
Raleigh, NC
Monitor comparison window 2023-07-15 to 2023-07-21 · PM2.5 target: Millbrook School
293% above nearby days
About the same as surrounding days
186% higher than surrounding days
293% higher than surrounding days
186% higher than surrounding days
62% higher than surrounding days
16% higher than surrounding days
About the same as surrounding days
38% higher than surrounding days
6% lower than surrounding days
About the same as surrounding days
About the same as surrounding days
About the same as 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 |
|---|---|---|---|---|
| Des Moines-West Des Moines, IA | 67.2 µg/m³ | 5.2 | Jul 16, 2023 | #3 of its top days |
| Cleveland-Elyria, OH | 63.5 µg/m³ | 2.9 | Jul 17, 2023 | #8 of its top days |
| Chicago-Naperville-Elgin, IL-IN-WI | 58.8 µg/m³ | 2.7 | Jul 16, 2023 | #23 of its top days |
| Columbus, OH | 58.7 µg/m³ | 2.7 | Jul 17, 2023 | #9 of its top days |
| Akron, OH | 58.6 µg/m³ | 2.7 | Jul 17, 2023 | #5 of its top days |
| Knoxville, TN | 54.8 µg/m³ | 2.5 | Jul 17, 2023 | #19 of its top days |
| Winston-Salem, NC | 54.2 µg/m³ | 4.6 | Jul 17, 2023 | #5 of its top days |
| Chattanooga, TN-GA | 53.5 µg/m³ | 2.4 | Jul 17, 2023 | #6 of its top days |
| Minneapolis-St. Paul-Bloomington, MN-WI | 51.4 µg/m³ | 2.3 | Jul 15, 2023 | #23 of its top days |
| Rochester, NY | 49.9 µg/m³ | 2.3 | Jul 17, 2023 | #5 of its top days |
| Dayton, OH | 48.2 µg/m³ | 2.2 | Jul 17, 2023 | #14 of its top days |
| Charlotte-Concord-Gastonia, NC-SC | 46.1 µg/m³ | 4.1 | Jul 18, 2023 | #6 of its top days |
| Greenville-Anderson-Mauldin, SC | 45.8 µg/m³ | 4.1 | Jul 18, 2023 | #9 of its top days |
| Raleigh, NC | 45.6 µg/m³ | 2.1 | Jul 18, 2023 | #7 of its top days |
| Syracuse, NY | 43.7 µg/m³ | 2.0 | Jul 17, 2023 | #11 of its top days |
| Columbia, SC | 40.4 µg/m³ | 1.8 | Jul 18, 2023 | #15 of its top days |
| Greensboro-High Point, NC | 40.3 µg/m³ | 3.6 | Jul 17, 2023 | #19 of its top days |
| Durham-Chapel Hill, NC | 36.7 µg/m³ | 1.7 | Jul 18, 2023 | #23 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 IT — Wildfire-U. S.
EPA AQS carries an agency-submitted informational qualifier (IT, Wildfire-U. S.) on 320 PM2.5 samples in the candidate CBSA on 2023-07-15, 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 408 PM2.5 samples in the candidate CBSA on 2023-07-16, 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 193 PM2.5 samples in the candidate CBSA on 2023-07-17, 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 RT — Wildfire-U. S.
EPA AQS carries an agency-submitted request-exclusion qualifier (RT, Wildfire-U. S.) on 49 PM2.5 samples in the candidate CBSA on 2023-07-17, identifying wildfire smoke as affecting the samples. A request-exclusion qualifier is an official submitting-agency causal claim, but this endpoint does not establish EPA concurrence.
AQS PM2.5 qualifier RF — Fire - Canadian.
EPA AQS carries an agency-submitted request-exclusion qualifier (RF, Fire - Canadian.) on 49 PM2.5 samples in the candidate CBSA on 2023-07-17, identifying wildfire smoke as affecting the samples. A request-exclusion qualifier is an official submitting-agency causal claim, but this endpoint does not establish EPA concurrence.
AQS PM2.5 qualifier IF — Fire - Canadian.
EPA AQS carries an agency-submitted informational qualifier (IF, Fire - Canadian.) on 49 PM2.5 samples in the candidate CBSA on 2023-07-17, 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 50 PM2.5 samples in the candidate CBSA on 2023-07-17, 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 51 PM2.5 samples in the candidate CBSA on 2023-07-17, 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 53 PM2.5 samples in the candidate CBSA on 2023-07-17, 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 RF — Fire - Canadian.
EPA AQS carries an agency-submitted request-exclusion qualifier (RF, Fire - Canadian.) on 24 PM2.5 samples in the candidate CBSA on 2023-07-17, identifying wildfire smoke as affecting the samples. A request-exclusion qualifier is an official submitting-agency causal claim, but this endpoint does not establish EPA concurrence.
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 2023-07-18, 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 97 PM2.5 samples in the candidate CBSA on 2023-07-18, 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 49 PM2.5 samples in the candidate CBSA on 2023-07-18, 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 86 PM2.5 samples in the candidate CBSA on 2023-07-17, 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 RF — Fire - Canadian.
EPA AQS carries an agency-submitted request-exclusion qualifier (RF, Fire - Canadian.) on 24 PM2.5 samples in the candidate CBSA on 2023-07-18, identifying wildfire smoke as affecting the samples. A request-exclusion qualifier is an official submitting-agency causal claim, but this endpoint does not establish EPA concurrence.
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 2023-07-17, 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 92 PM2.5 samples in the candidate CBSA on 2023-07-17, 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 RF — Fire - Canadian.
EPA AQS carries an agency-submitted request-exclusion qualifier (RF, Fire - Canadian.) on 25 PM2.5 samples in the candidate CBSA on 2023-07-17, identifying wildfire smoke as affecting the samples. A request-exclusion qualifier is an official submitting-agency causal claim, but this endpoint does not establish EPA concurrence.
AQS PM2.5 qualifier IF — Fire - Canadian.
EPA AQS carries an agency-submitted informational qualifier (IF, Fire - Canadian.) on 121 PM2.5 samples in the candidate CBSA on 2023-07-18, 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 RF — Fire - Canadian.
EPA AQS carries an agency-submitted request-exclusion qualifier (RF, Fire - Canadian.) on 24 PM2.5 samples in the candidate CBSA on 2023-07-18, identifying wildfire smoke as affecting the samples. A request-exclusion qualifier is an official submitting-agency causal claim, but this endpoint does not establish EPA concurrence.
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 2023-07-17, 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 51 PM2.5 samples in the candidate CBSA on 2023-07-17, 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 23 PM2.5 samples in the candidate CBSA on 2023-07-18, 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 2023-07-18, 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 95 PM2.5 samples in the candidate CBSA on 2023-07-18, 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, July 16, 2023
Iowa DNR explicitly identified Canadian wildfire smoke affecting the Des Moines-area episode through July 16. IEM is the archive, not the official system of record.
Archived Chicago Air Quality Alert, July 16, 2023
Illinois EPA alerts explicitly identified wildfire smoke affecting Chicago during the event. IEM is the archive, not the official system of record.
Ohio EPA describes Canadian wildfire smoke moving into the Ohio Valley and building at the surface across northern Ohio on July 16–17.
Ohio’s Exceptional Events Demonstration for 2023
Ohio EPA concludes the July 16–17 Great Lakes and northeastern-Ohio episode was transported Canadian wildfire smoke rather than a local source.
Unhealthy Air Possible in NC This Week Due to Canadian Wildfires
North Carolina DEQ reported that a plume of smoke from Canadian wildfires was entering the state and forecast unhealthy fine-particle conditions for central and western North Carolina.
DNR Issues Statewide Air Quality Advisory Due To Canadian Wildfire Smoke
Wisconsin DNR forecast smoke from western Canadian wildfires across the Upper Midwest for July 14–16.
Illinois officials reported that wildfire smoke had caused unusually severe Illinois air-quality conditions in recent weeks.
Federal Agency Issues New Air Quality Alerts Targeting Much of Northern US
Contemporaneous reporting of the National Weather Service forecast says Canadian-Prairie smoke was directed into the Lower 48 and that air-quality alerts included central Tennessee.
Air quality health advisories in effect across New York on Monday due to Canadian wildfire smoke
Contemporaneous coverage reports statewide New York health advisories as smoke from Canadian wildfires returned to the state.
Air quality starts improving and humidity drops Monday
KCCI reported unhealthy air and ground-level smoke across central Iowa on July 16 and explained that changing winds would shift transport away from Canadian fires.
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.