SmogRank / Episodes / Canada
Alberta, Saskatchewan and British Columbia, Canada, June 2023
For 9 days, from 8 to 16 June 2023, 21 cities in Canada had PM2.5 at least twice their usual for the time of year. The worst reading was Grande Prairie, Alberta, Canada: 163.0 µg/m³ on 14 June, about 31× its usual 5.3. Ended 16 June.
Likely smoke from fires Fires were detected within 300 km of the city on 82% of the counted city-days and smoke was mapped over the city on 100%. Satellites see crop, field and forest fires alike, so this doesn't say which burned.
Cities reached 21 in 1 country
Days 9 8 to 16 June 2023
Worst day 9 June 14 cities counted
Furthest above usual 31× Grande Prairie
Day by day
Play 9 June 14 cities at twice their usual or more
Cranbrook Medicine Hat Creston Vernon Kelowna Penticton Kamloops Fort St. John Hope Agassiz Chilliwack Abbotsford Lynden Whistler Bellingham Langley Port Coquitlam Coquitlam Strawberry Hill Burnaby Squamish North Vancouver Delta Vancouver West Vancouver Richmond Gibsons North Cowichan Duncan Nanaimo Harewood Quesnel Castlegar Williams Lake Regina Red Deer Drayton Valley St. Albert Sherwood Park Swift Current Edmonton Calgary Fort Saskatchewan Prince George Lethbridge Airdrie Grand Centre Edson Prince Albert Saskatoon Fort McMurray Grande Prairie 5 Jun 6 7 8 9 10 11 12 13 14 15 16 17 18 19 Every measured city in the area, coloured by its PM2.5 that day; a dark ring marks a city at twice its usual or more. Bars: cities counted each day, coloured by their median level. Choose a day or press play; without JavaScript, the days link to that day's world ranking.
How it spread
Grande Prairie Grande Prairie, 5 June: 5.5 µg/m³ Grande Prairie, 6 June: 9.0 µg/m³ Grande Prairie, 7 June: 40.5 µg/m³ Grande Prairie, 8 June: 58.9 µg/m³, 11× its usual 5.5 Grande Prairie, 9 June: 65.8 µg/m³, 12× its usual 5.4 Grande Prairie, 10 June: 75.2 µg/m³, 14× its usual 5.3 Grande Prairie, 11 June: 66.9 µg/m³, 13× its usual 5.0 Grande Prairie, 12 June: 97.7 µg/m³, 20× its usual 5.0 Grande Prairie, 13 June: 73.4 µg/m³, 14× its usual 5.3 Grande Prairie, 14 June: 163.0 µg/m³, 31× its usual 5.3 Grande Prairie, 15 June: 68.5 µg/m³, 13× its usual 5.1 Grande Prairie, 16 June: 18.8 µg/m³ Grande Prairie, 17 June: 3.0 µg/m³ Grande Prairie, 18 June: 16.9 µg/m³ Grande Prairie, 19 June: 7.6 µg/m³ Grand Centre Grand Centre, 5 June: 9.3 µg/m³ Grand Centre, 6 June: 5.8 µg/m³ Grand Centre, 7 June: 7.0 µg/m³ Grand Centre, 8 June: 50.2 µg/m³, 9.7× its usual 5.2 Grand Centre, 9 June: 39.4 µg/m³, 7.6× its usual 5.2 Grand Centre, 10 June: 24.4 µg/m³ Grand Centre, 11 June: 18.1 µg/m³ Grand Centre, 12 June: 70.9 µg/m³, 13× its usual 5.5 Grand Centre, 13 June: 46.3 µg/m³, 8.0× its usual 5.8 Grand Centre, 14 June: 18.5 µg/m³ Grand Centre, 15 June: 15.4 µg/m³ Grand Centre, 16 June: 31.5 µg/m³, 5.1× its usual 6.2 Grand Centre, 17 June: 5.0 µg/m³ Grand Centre, 18 June: 45.5 µg/m³ Grand Centre, 19 June: 10.1 µg/m³ Fort McMurray Fort McMurray, 5 June: 15.3 µg/m³ Fort McMurray, 6 June: 5.3 µg/m³ Fort McMurray, 7 June: 37.9 µg/m³ Fort McMurray, 8 June: 45.6 µg/m³, 8.1× its usual 5.6 Fort McMurray, 9 June: 27.6 µg/m³, 4.8× its usual 5.7 Fort McMurray, 10 June: 41.6 µg/m³ Fort McMurray, 11 June: 41.9 µg/m³ Fort McMurray, 12 June: 131.5 µg/m³, 22× its usual 6.1 Fort McMurray, 13 June: 76.3 µg/m³, 12× its usual 6.3 Fort McMurray, 14 June: 15.0 µg/m³ Fort McMurray, 15 June: 17.7 µg/m³ Fort McMurray, 16 June: 9.9 µg/m³ Fort McMurray, 17 June: 13.4 µg/m³ Fort McMurray, 18 June: 11.0 µg/m³ Fort McMurray, 19 June: 4.7 µg/m³ Fort Saskatchewan Fort Saskatchewan, 5 June: 8.4 µg/m³ Fort Saskatchewan, 6 June: 6.4 µg/m³ Fort Saskatchewan, 7 June: 9.7 µg/m³ Fort Saskatchewan, 8 June: 45.4 µg/m³, 7.3× its usual 6.2 Fort Saskatchewan, 9 June: 60.1 µg/m³, 9.9× its usual 6.1 Fort Saskatchewan, 10 June: 43.4 µg/m³, 7.0× its usual 6.2 Fort Saskatchewan, 11 June: 34.7 µg/m³, 5.6× its usual 6.2 Fort Saskatchewan, 12 June: 60.6 µg/m³, 9.9× its usual 6.1 Fort Saskatchewan, 13 June: 45.9 µg/m³, 7.3× its usual 6.3 Fort Saskatchewan, 14 June: 36.2 µg/m³, 5.6× its usual 6.5 Fort Saskatchewan, 15 June: 24.4 µg/m³ Fort Saskatchewan, 16 June: 32.9 µg/m³, 4.9× its usual 6.7 Fort Saskatchewan, 17 June: 3.7 µg/m³ Fort Saskatchewan, 18 June: 8.9 µg/m³ Fort Saskatchewan, 19 June: 15.2 µg/m³ Edson Edson, 5 June: 3.9 µg/m³ Edson, 6 June: 7.9 µg/m³ Edson, 7 June: 12.3 µg/m³ Edson, 8 June: 42.5 µg/m³, 7.3× its usual 5.8 Edson, 9 June: 68.4 µg/m³, 12× its usual 5.6 Edson, 10 June: 77.6 µg/m³, 14× its usual 5.6 Edson, 11 June: 34.9 µg/m³, 6.2× its usual 5.6 Edson, 12 June: 95.7 µg/m³, 17× its usual 5.8 Edson, 13 June: 54.2 µg/m³, 9.7× its usual 5.6 Edson, 14 June: 36.3 µg/m³, 6.3× its usual 5.8 Edson, 15 June: 55.8 µg/m³, 9.6× its usual 5.8 Edson, 16 June: 24.4 µg/m³ Edson, 17 June: 1.6 µg/m³ Edson, 18 June: 0.7 µg/m³ Edson, 19 June: 3.8 µg/m³ Edmonton Edmonton, 5 June: 11.6 µg/m³ Edmonton, 6 June: 8.8 µg/m³ Edmonton, 7 June: 12.8 µg/m³ Edmonton, 8 June: 42.1 µg/m³, 6.1× its usual 6.9 Edmonton, 9 June: 60.6 µg/m³, 8.8× its usual 6.9 Edmonton, 10 June: 42.8 µg/m³, 6.1× its usual 7.0 Edmonton, 11 June: 39.1 µg/m³, 5.6× its usual 7.0 Edmonton, 12 June: 58.9 µg/m³, 8.4× its usual 7.0 Edmonton, 13 June: 41.6 µg/m³, 5.9× its usual 7.1 Edmonton, 14 June: 50.2 µg/m³, 6.8× its usual 7.4 Edmonton, 15 June: 28.8 µg/m³, 3.9× its usual 7.4 Edmonton, 16 June: 42.1 µg/m³, 5.4× its usual 7.8 Edmonton, 17 June: 6.7 µg/m³ Edmonton, 18 June: 10.4 µg/m³ Edmonton, 19 June: 18.2 µg/m³ Prince Albert Prince Albert, 5 June: 9.5 µg/m³ Prince Albert, 6 June: 8.4 µg/m³ Prince Albert, 7 June: 9.1 µg/m³ Prince Albert, 8 June: 38.5 µg/m³, 5.4× its usual 7.1 Prince Albert, 9 June: 31.8 µg/m³, 4.4× its usual 7.2 Prince Albert, 10 June: 20.5 µg/m³ Prince Albert, 11 June: 14.8 µg/m³ Prince Albert, 12 June: 106.0 µg/m³, 14× its usual 7.7 Prince Albert, 13 June: 151.0 µg/m³, 19× its usual 8.0 Prince Albert, 14 June: 25.1 µg/m³ Prince Albert, 15 June: 12.1 µg/m³ Prince Albert, 16 June: 19.8 µg/m³ Prince Albert, 17 June: 19.3 µg/m³ Prince Albert, 18 June: 15.3 µg/m³ Prince Albert, 19 June: 5.3 µg/m³ St. Albert St. Albert, 5 June: 7.0 µg/m³ St. Albert, 6 June: 8.9 µg/m³ St. Albert, 7 June: 14.7 µg/m³ St. Albert, 8 June: 38.4 µg/m³, 6.5× its usual 5.9 St. Albert, 9 June: 36.4 µg/m³, 6.2× its usual 5.9 St. Albert, 10 June: 27.1 µg/m³, 4.6× its usual 5.9 St. Albert, 11 June: 20.9 µg/m³ St. Albert, 12 June: 46.3 µg/m³, 7.5× its usual 6.2 St. Albert, 13 June: 22.3 µg/m³ St. Albert, 14 June: 25.4 µg/m³, 4.0× its usual 6.3 St. Albert, 15 June: 17.2 µg/m³ St. Albert, 16 June: 30.9 µg/m³, 4.8× its usual 6.5 St. Albert, 17 June: 2.0 µg/m³ St. Albert, 18 June: 4.6 µg/m³ St. Albert, 19 June: 8.3 µg/m³ Saskatoon Saskatoon, 5 June: 8.3 µg/m³ Saskatoon, 6 June: 10.9 µg/m³ Saskatoon, 7 June: 10.5 µg/m³ Saskatoon, 8 June: 32.1 µg/m³, 5.1× its usual 6.3 Saskatoon, 9 June: 60.3 µg/m³, 9.6× its usual 6.3 Saskatoon, 10 June: 21.1 µg/m³ Saskatoon, 11 June: 16.3 µg/m³ Saskatoon, 12 June: 55.4 µg/m³, 8.4× its usual 6.6 Saskatoon, 13 June: 131.0 µg/m³, 20× its usual 6.6 Saskatoon, 14 June: 31.0 µg/m³ Saskatoon, 15 June: 13.6 µg/m³ Saskatoon, 16 June: 37.5 µg/m³, 5.5× its usual 6.8 Saskatoon, 17 June: 21.8 µg/m³ Saskatoon, 18 June: 9.4 µg/m³ Saskatoon, 19 June: 3.4 µg/m³ Sherwood Park Sherwood Park, 5 June: no reading Sherwood Park, 6 June: no reading Sherwood Park, 7 June: no reading Sherwood Park, 8 June: 28.7 µg/m³, 5.7× its usual 5.0 Sherwood Park, 9 June: 39.4 µg/m³, 7.9× its usual 5.0 Sherwood Park, 10 June: 29.1 µg/m³, 5.6× its usual 5.2 Sherwood Park, 11 June: 22.6 µg/m³ Sherwood Park, 12 June: 37.2 µg/m³, 7.0× its usual 5.3 Sherwood Park, 13 June: 34.1 µg/m³, 6.4× its usual 5.3 Sherwood Park, 14 June: 32.2 µg/m³, 6.1× its usual 5.3 Sherwood Park, 15 June: 17.5 µg/m³ Sherwood Park, 16 June: 25.7 µg/m³, 4.8× its usual 5.4 Sherwood Park, 17 June: 2.6 µg/m³ Sherwood Park, 18 June: 5.3 µg/m³ Sherwood Park, 19 June: 8.5 µg/m³ Swift Current Swift Current, 5 June: 7.8 µg/m³ Swift Current, 6 June: 10.5 µg/m³ Swift Current, 7 June: 8.6 µg/m³ Swift Current, 8 June: 7.5 µg/m³ Swift Current, 9 June: 40.7 µg/m³, 8.1× its usual 4.4 Swift Current, 10 June: 25.8 µg/m³ Swift Current, 11 June: 16.7 µg/m³ Swift Current, 12 June: 13.7 µg/m³ Swift Current, 13 June: 13.8 µg/m³ Swift Current, 14 June: 9.7 µg/m³ Swift Current, 15 June: 18.2 µg/m³ Swift Current, 16 June: 36.9 µg/m³, 7.4× its usual 4.7 Swift Current, 17 June: 20.0 µg/m³ Swift Current, 18 June: 7.3 µg/m³ Swift Current, 19 June: 2.8 µg/m³ Regina Regina, 5 June: no reading Regina, 6 June: no reading Regina, 7 June: 9.5 µg/m³ Regina, 8 June: 6.5 µg/m³ Regina, 9 June: 38.4 µg/m³, 7.2× its usual 5.3 Regina, 10 June: 16.3 µg/m³ Regina, 11 June: no reading Regina, 12 June: no reading Regina, 13 June: 13.8 µg/m³ Regina, 14 June: 29.3 µg/m³ Regina, 15 June: 9.3 µg/m³ Regina, 16 June: 22.7 µg/m³ Regina, 17 June: 21.7 µg/m³ Regina, 18 June: 9.5 µg/m³ Regina, 19 June: 3.5 µg/m³ Drayton Valley Drayton Valley, 5 June: 5.6 µg/m³ Drayton Valley, 6 June: 9.8 µg/m³ Drayton Valley, 7 June: 15.1 µg/m³ Drayton Valley, 8 June: 20.6 µg/m³ Drayton Valley, 9 June: 34.8 µg/m³, 5.6× its usual 6.2 Drayton Valley, 10 June: 31.1 µg/m³, 4.7× its usual 6.6 Drayton Valley, 11 June: 47.3 µg/m³, 7.2× its usual 6.6 Drayton Valley, 12 June: 44.1 µg/m³, 6.7× its usual 6.6 Drayton Valley, 13 June: 36.6 µg/m³, 5.5× its usual 6.6 Drayton Valley, 14 June: 37.4 µg/m³, 5.7× its usual 6.6 Drayton Valley, 15 June: 34.9 µg/m³, 5.3× its usual 6.6 Drayton Valley, 16 June: 26.7 µg/m³, 4.0× its usual 6.6 Drayton Valley, 17 June: 4.0 µg/m³ Drayton Valley, 18 June: 3.2 µg/m³ Drayton Valley, 19 June: 7.6 µg/m³ Airdrie Airdrie, 5 June: 10.3 µg/m³ Airdrie, 6 June: 15.0 µg/m³ Airdrie, 7 June: 15.9 µg/m³ Airdrie, 8 June: 17.2 µg/m³ Airdrie, 9 June: 25.3 µg/m³, 5.1× its usual 4.7 Airdrie, 10 June: 14.2 µg/m³ Airdrie, 11 June: 39.8 µg/m³, 8.0× its usual 5.0 Airdrie, 12 June: 16.3 µg/m³ Airdrie, 13 June: 18.5 µg/m³ Airdrie, 14 June: 17.5 µg/m³ Airdrie, 15 June: 61.2 µg/m³, 12× its usual 5.0 Airdrie, 16 June: 16.9 µg/m³ Airdrie, 17 June: 9.0 µg/m³ Airdrie, 18 June: 1.9 µg/m³ Airdrie, 19 June: 2.3 µg/m³ Calgary Calgary, 5 June: 12.5 µg/m³ Calgary, 6 June: 11.4 µg/m³ Calgary, 7 June: 14.8 µg/m³ Calgary, 8 June: 14.6 µg/m³ Calgary, 9 June: 20.0 µg/m³ Calgary, 10 June: 14.5 µg/m³ Calgary, 11 June: 48.5 µg/m³, 8.1× its usual 6.0 Calgary, 12 June: 15.9 µg/m³ Calgary, 13 June: 13.1 µg/m³ Calgary, 14 June: 6.9 µg/m³ Calgary, 15 June: 57.0 µg/m³, 9.2× its usual 6.2 Calgary, 16 June: 29.5 µg/m³, 4.8× its usual 6.2 Calgary, 17 June: 4.7 µg/m³ Calgary, 18 June: 2.6 µg/m³ Calgary, 19 June: 1.2 µg/m³ Red Deer Red Deer, 5 June: 9.6 µg/m³ Red Deer, 6 June: 5.6 µg/m³ Red Deer, 7 June: 9.4 µg/m³ Red Deer, 8 June: 14.2 µg/m³ Red Deer, 9 June: 24.7 µg/m³ Red Deer, 10 June: 24.3 µg/m³ Red Deer, 11 June: 42.5 µg/m³, 7.2× its usual 5.9 Red Deer, 12 June: 36.9 µg/m³, 6.1× its usual 6.0 Red Deer, 13 June: 28.2 µg/m³, 4.6× its usual 6.1 Red Deer, 14 June: 30.9 µg/m³, 5.1× its usual 6.1 Red Deer, 15 June: 37.9 µg/m³, 6.1× its usual 6.2 Red Deer, 16 June: 36.6 µg/m³, 5.9× its usual 6.2 Red Deer, 17 June: 4.0 µg/m³ Red Deer, 18 June: 2.9 µg/m³ Red Deer, 19 June: 1.4 µg/m³ Lethbridge Lethbridge, 5 June: 8.6 µg/m³ Lethbridge, 6 June: 9.0 µg/m³ Lethbridge, 7 June: 9.6 µg/m³ Lethbridge, 8 June: 11.3 µg/m³ Lethbridge, 9 June: 12.3 µg/m³ Lethbridge, 10 June: 10.9 µg/m³ Lethbridge, 11 June: 14.5 µg/m³ Lethbridge, 12 June: 26.2 µg/m³, 5.2× its usual 4.5 Lethbridge, 13 June: 17.4 µg/m³ Lethbridge, 14 June: 3.9 µg/m³ Lethbridge, 15 June: 52.3 µg/m³, 10× its usual 4.7 Lethbridge, 16 June: 21.1 µg/m³ Lethbridge, 17 June: 5.2 µg/m³ Lethbridge, 18 June: 3.2 µg/m³ Lethbridge, 19 June: 2.9 µg/m³ Prince George Prince George, 5 June: 3.6 µg/m³ Prince George, 6 June: 9.4 µg/m³ Prince George, 7 June: 14.8 µg/m³ Prince George, 8 June: 19.7 µg/m³ Prince George, 9 June: 16.8 µg/m³ Prince George, 10 June: 9.2 µg/m³ Prince George, 11 June: 6.2 µg/m³ Prince George, 12 June: 7.5 µg/m³ Prince George, 13 June: 7.2 µg/m³ Prince George, 14 June: 52.3 µg/m³, 10× its usual 5.1 Prince George, 15 June: 32.0 µg/m³, 6.0× its usual 5.3 Prince George, 16 June: 4.9 µg/m³ Prince George, 17 June: 5.2 µg/m³ Prince George, 18 June: 8.1 µg/m³ Prince George, 19 June: 9.0 µg/m³ Quesnel Quesnel, 5 June: 3.4 µg/m³ Quesnel, 6 June: 7.7 µg/m³ Quesnel, 7 June: 14.2 µg/m³ Quesnel, 8 June: 14.7 µg/m³ Quesnel, 9 June: 21.2 µg/m³ Quesnel, 10 June: 11.7 µg/m³ Quesnel, 11 June: 5.6 µg/m³ Quesnel, 12 June: 10.4 µg/m³ Quesnel, 13 June: 7.1 µg/m³ Quesnel, 14 June: 26.8 µg/m³, 4.5× its usual 6.0 Quesnel, 15 June: 24.2 µg/m³ Quesnel, 16 June: 2.8 µg/m³ Quesnel, 17 June: 2.1 µg/m³ Quesnel, 18 June: 6.6 µg/m³ Quesnel, 19 June: 6.6 µg/m³ Williams Lake Williams Lake, 5 June: 3.4 µg/m³ Williams Lake, 6 June: 5.7 µg/m³ Williams Lake, 7 June: 6.3 µg/m³ Williams Lake, 8 June: 8.8 µg/m³ Williams Lake, 9 June: 14.1 µg/m³ Williams Lake, 10 June: 11.3 µg/m³ Williams Lake, 11 June: 4.9 µg/m³ Williams Lake, 12 June: 6.1 µg/m³ Williams Lake, 13 June: 6.4 µg/m³ Williams Lake, 14 June: 26.3 µg/m³, 5.3× its usual 3.5 Williams Lake, 15 June: 23.1 µg/m³ Williams Lake, 16 June: 1.3 µg/m³ Williams Lake, 17 June: 2.3 µg/m³ Williams Lake, 18 June: 5.3 µg/m³ Williams Lake, 19 June: 5.5 µg/m³ Castlegar Castlegar, 5 June: 9.3 µg/m³ Castlegar, 6 June: 6.6 µg/m³ Castlegar, 7 June: 10.4 µg/m³ Castlegar, 8 June: 10.4 µg/m³ Castlegar, 9 June: 10.5 µg/m³ Castlegar, 10 June: 7.6 µg/m³ Castlegar, 11 June: 6.0 µg/m³ Castlegar, 12 June: 11.3 µg/m³ Castlegar, 13 June: 12.9 µg/m³ Castlegar, 14 June: 9.1 µg/m³ Castlegar, 15 June: 24.6 µg/m³ Castlegar, 16 June: 27.0 µg/m³, 5.2× its usual 5.2 Castlegar, 17 June: 5.5 µg/m³ Castlegar, 18 June: 1.1 µg/m³ Castlegar, 19 June: 2.5 µg/m³ 5 Jun 7 9 11 13 15 17 19 Every counted city, in the order the episode reached them, 3 days before to 3 after. Each square is a day, coloured by that day's PM2.5; outlined: at twice the city's usual or more. Good 0–50
Moderate 51–100
Sensitive groups 101–150
Unhealthy 151–200
Very unhealthy 201–300
Hazardous 301+
Every city it reached
City Days Highest Usual Above usual
Grande Prairie Alberta, Canada 8 14 June 5.3 31× Fort McMurray Alberta, Canada 4 12 June 6.1 22× Saskatoon Saskatchewan, Canada 5 13 June 6.6 20× Prince Albert Saskatchewan, Canada 4 13 June 8.0 19× Edson Alberta, Canada 8 12 June 5.8 17× Grand Centre Alberta, Canada 5 12 June 5.5 13× Airdrie Alberta, Canada 3 15 June 5.0 12× Lethbridge Alberta, Canada 2 15 June 4.7 11× Prince George British Columbia, Canada 2 14 June 5.1 10× Fort Saskatchewan Alberta, Canada 8 12 June 6.1 9.9× Calgary Alberta, Canada 3 15 June 6.2 9.2× Edmonton Alberta, Canada 9 9 June 6.9 8.8× Swift Current Saskatchewan, Canada 2 9 June 4.4 8.1× Sherwood Park Alberta, Canada 7 9 June 5.0 7.9× St. Albert Alberta, Canada 6 12 June 6.2 7.5× Drayton Valley Alberta, Canada 8 11 June 6.6 7.2× Red Deer Alberta, Canada 6 11 June 5.9 7.2× Regina Saskatchewan, Canada 1 9 June 5.3 7.2× Williams Lake British Columbia, Canada 1 14 June 3.5 5.3× Castlegar British Columbia, Canada 1 16 June 5.2 5.2× Quesnel British Columbia, Canada 1 14 June 6.0 4.5×
Daily means in µg/m³, over the days each city counted in this episode. Highest: its highest of those days. Usual: the city's median for the time of year of that day (its days within 21 days of the date, every year, leaving out the week around it). Above usual: its highest day against that, with a usual under 5 µg/m³ taken as 5.
Against other episodes in Canada
Number 14 of 43 episodes in Canada since our records began, by cities reached.
North-western United States and Canada, August 2023 176 Northern United States and Canada, July 2025 139 North-western United States and Canada, July and August 2026 118 North-western United States and Canada, August and September 2025 94 North-western United States and Canada, July 2024 92 Northern United States and Canada, May 2023 83 Northern United States and Canada, August and September 2023 82 North-western United States and Canada, May 2023 63 North-western Canada and United States, September 2025 57 North-eastern United States and Canada, March 2026 40 North-western Canada and United States, June 2025 28 South-eastern Canada and United States, December 2024 27 Alberta, Saskatchewan and British Columbia, Canada, June 2023 21 Bars: cities reached; colour: the level of the episode's highest daily reading. All 43 .
Use this page SmogRank, Alberta, Saskatchewan and British Columbia, Canada, June 2023: 21 cities with PM2.5 at twice their usual or more, 8 to 16 June 2023, smogrank.com/episodes/2023-06-alberta-saskatchewan-and-british-columbia-canada (accessed 5 October 2026).
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You're welcome to reuse a single chart, image or figure with this citation and a link. Terms .
An episode is a run of days when many cities close to each other (four or more within 350 km on a day, 8 or more in all) each had a daily PM2.5 mean of at least 25 µg/m³ and at least 2 times their usual for that time of year. Found in our own measurements, not picked by hand. How we find episodes . Values are each city's daily mean of its own monitors; causes are the usual kinds for a pattern like this, not a confirmed source. Fire detections from NASA FIRMS; smoke maps from NOAA HMS.
