Wildfire smoke
2023 early-June Canadian wildfire-smoke episode
Daily PM2.5 peaked at 258.9 µg/m³ near Allentown across 25 covered metros home to 63 million people. 12 metros recorded their worst day on record; 20 placed a top-ten day.
Counting the extra PM2.5 above each metro's typical day, this event handed the average affected resident ≈ 11.3 cigarettes. Across everyone living in the affected metros, that is the collective equivalent of ≈ 710 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 9 other supplied events because the evidence identifies Canada as the shared origin and the affected intervals form one continuous 2023-06-04 through 2023-06-09 occurrence. Qualified supplied evidence supports wildfire smoke for this event. It is grouped with 9 other supplied events because the evidence identifies Canada as the shared origin and the affected intervals form one continuous 2023-06-04 through 2023-06-09 occurrence. Qualified supplied evidence supports wildfire smoke for this event. It is grouped with 9 other supplied events because the evidence identifies Canada as the shared origin and the affected intervals form one continuous 2023-06-04 through 2023-06-09 occurrence. Qualified supplied e
Sequence: Madison (Jun 4) → Allentown (Jun 6) → Philadelphia (Jun 6) → Scranton (Jun 6) → New York (Jun 6) → Syracuse (Jun 6) → Harrisburg (Jun 6) → Bridgeport (Jun 6) → New Haven (Jun 6) → Albany (Jun 6) → +15 more metros
Affected metros
| Metro | Peak PM2.5 | Cigarettes, whole event | Peak day | All-time standing |
|---|---|---|---|---|
| Allentown-Bethlehem-Easton, PA-NJ | 258.9 µg/m³ | 21.1 | Jun 7, 2023 | Worst day on record |
| Philadelphia-Camden-Wilmington, PA-NJ-DE-MD | 240.8 µg/m³ | 22.1 | Jun 7, 2023 | Worst day on record |
| Scranton--Wilkes-Barre--Hazleton, PA | 217.7 µg/m³ | 18.6 | Jun 7, 2023 | Worst day on record |
| New York-Newark-Jersey City, NY-NJ-PA | 203.5 µg/m³ | 19.0 | Jun 7, 2023 | Worst day on record |
| Syracuse, NY | 182.6 µg/m³ | 14.1 | Jun 7, 2023 | Worst day on record |
| Harrisburg-Carlisle, PA | 180 µg/m³ | 17.9 | Jun 8, 2023 | Worst day on record |
| Bridgeport-Stamford-Norwalk, CT | 166.6 µg/m³ | 15.7 | Jun 7, 2023 | Worst day on record |
| Washington-Arlington-Alexandria, DC-VA-MD-WV | 146.8 µg/m³ | 11.4 | Jun 8, 2023 | #2 of its top days |
| New Haven-Milford, CT | 132.5 µg/m³ | 13.0 | Jun 7, 2023 | Worst day on record |
| Baltimore-Columbia-Towson, MD | 125.3 µg/m³ | 9.5 | Jun 8, 2023 | Worst day on record |
| Albany-Schenectady-Troy, NY | 105.5 µg/m³ | 11.5 | Jun 7, 2023 | Worst day on record |
| Virginia Beach-Norfolk-Newport News, VA-NC | 88.4 µg/m³ | 4.0 | Jun 7, 2023 | Worst day on record |
| Hartford-West Hartford-East Hartford, CT | 77.6 µg/m³ | 9.6 | Jun 7, 2023 | Worst day on record |
| Detroit-Warren-Dearborn, MI | 66.8 µg/m³ | 3.0 | Jun 7, 2023 | #13 of its top days |
| Springfield, MA | 58.5 µg/m³ | 7.7 | Jun 8, 2023 | #5 of its top days |
| Cincinnati, OH-KY-IN | 57.7 µg/m³ | 2.6 | Jun 7, 2023 | #5 of its top days |
| Richmond, VA | 57.1 µg/m³ | 5.2 | Jun 7, 2023 | #3 of its top days |
| Dayton, OH | 54.5 µg/m³ | 4.5 | Jun 7, 2023 | #7 of its top days |
| Cleveland-Elyria, OH | 54.5 µg/m³ | 2.5 | Jun 7, 2023 | #25 of its top days |
| Worcester, MA-CT | 54.4 µg/m³ | 2.5 | Jun 6, 2023 | #3 of its top days |
| Columbus, OH | 51.4 µg/m³ | 2.3 | Jun 7, 2023 | #16 of its top days |
| Providence-Warwick, RI-MA | 50.3 µg/m³ | 4.6 | Jun 6, 2023 | #5 of its top days |
| Madison, WI | 45.7 µg/m³ | 2.1 | Jun 4, 2023 | #15 of its top days |
| Raleigh, NC | 45.2 µg/m³ | 3.8 | Jun 9, 2023 | #9 of its top days |
| Winston-Salem, NC | 41.7 µg/m³ | 1.9 | Jun 6, 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.
The evidence
EPA AQS monitor qualifier 59
- 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 2023-06-04, 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 RF — Fire - Canadian. EPA AQS carries an agency-submitted request-exclusion qualifier (RF, Fire - Canadian.) on 48 PM2.5 samples in the candidate CBSA on 2023-06-06, 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 2023-06-07, 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 431 PM2.5 samples in the candidate CBSA on 2023-06-07, 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 RF — Fire - Canadian. EPA AQS carries an agency-submitted request-exclusion qualifier (RF, Fire - Canadian.) on 48 PM2.5 samples in the candidate CBSA on 2023-06-07, 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 432 PM2.5 samples in the candidate CBSA on 2023-06-06, 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 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 2023-06-06, 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 2023-06-06, 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 32 PM2.5 samples in the candidate CBSA on 2023-06-06, 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 120 PM2.5 samples in the candidate CBSA on 2023-06-07, 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 40 PM2.5 samples in the candidate CBSA on 2023-06-06, 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 310 PM2.5 samples in the candidate CBSA on 2023-06-06, 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.
- +47 more EPA AQS records on file
NWS Air Quality Alert 2
- Archived New Jersey Air Quality Alert, June 6, 2023 The New Jersey alert explicitly attributed elevated fine-particle levels to smoke from eastern Canadian wildfires. IEM is the archive, not the official system of record.
- Archived New York State Air Quality Alert, June 7, 2023 New York State alerts explicitly attributed elevated fine-particle levels to smoke transported from eastern Canadian wildfires. IEM is the archive, not the official system of record.
Agency and publisher pages 7
- Wildfire Smoke Transport from Canada to US NASA satellite analysis describes smoke from Canadian wildfires transported to the Great Lakes region of Michigan and Ohio and creating localized pollution during June 1–8, 2023.
- Widespread Code Orange Air Quality Action Day Issued due to Canadian Wildfire Smoke North Carolina DEQ issued a June 6 action day because Canadian wildfire smoke was raising fine-particle pollution across much of the state.
- Canadian Wildfires Prompt Poor Air Quality Alert for Connecticut, Massachusetts, New Hampshire, Rhode Island, and Vermont on June 6, 2023 EPA forecast elevated fine-particle pollution from wildfires in Quebec and northern Ontario across Connecticut, Massachusetts, and Rhode Island on June 6.
- Notes from the Field: Asthma-Associated Emergency Department Visits During a Wildfire Smoke Event — New York, June 2023 CDC states that smoke from Eastern Canadian wildfires caused poor PM2.5-driven air quality across New York during June 6–8.
- Pennsylvania under Code Red Air Quality Alert Due to Wildfire Smoke Pennsylvania DEP declared a statewide fine-particle Code Red action day on June 7 because of wildfire smoke.
- Air Quality Alert in Washington, DC Elevated to Code Purple DC identified smoke from Canadian wildfires as causing unhealthy air quality in Washington and the Northeast.
- Fires Lower Outdoor Air Quality in Virginia Virginia Department of Health reported that wildfire-smoke particles from Canada were being carried by wind into much of Virginia.
News discovery (GDELT) 1
- 'It was hazy.' People in Triangle react to air quality from Northeast Canada wildfire smoke ABC11 reported that smoke from rapidly burning Northeast Canada wildfires reached Raleigh and the Triangle, triggering a Code Red air-quality alert and fine-particle health warnings.
What remains uncertain
- Agency-submitted AQS qualifiers are causal flags but do not by themselves establish EPA concurrence.
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.