SmogRank / Episodes / Canada

Alberta, Saskatchewan and Manitoba, Canada, May and June 2025

For 3 days, from 30 May to 1 June 2025, 9 cities in Canada had PM2.5 at least twice their usual for the time of year. The worst reading was Fort McMurray, Alberta, Canada: 262.0 µg/m³ on 30 May, about 48× its usual 5.5. Ended 1 June.

No cause namedWe have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached9in 1 country
Days330 May to 1 June 2025
Worst day30 May9 cities counted
Furthest above usual48×Fort McMurray

Day by day

30 May 9 cities at twice their usual or more
Swift CurrentMedicine HatHavreSherwood ParkEdmontonLethbridgeRed DeerAirdrieCalgaryFort SaskatchewanSt. AlbertSaskatoonPrince AlbertGrand CentreReginaEstevanFlin FlonFort McMurray
27 May282930311 Jun234
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

Fort McMurrayFort McMurray, 27 May: 10.3 µg/m³Fort McMurray, 28 May: 6.7 µg/m³Fort McMurray, 29 May: 54.1 µg/m³Fort McMurray, 30 May: 262.0 µg/m³, 48× its usual 5.5Fort McMurray, 31 May: 140.0 µg/m³, 26× its usual 5.3Fort McMurray, 1 June: 47.4 µg/m³, 8.6× its usual 5.5Fort McMurray, 2 June: 39.2 µg/m³Fort McMurray, 3 June: 16.0 µg/m³Fort McMurray, 4 June: 21.8 µg/m³Prince AlbertPrince Albert, 27 May: 5.3 µg/m³Prince Albert, 28 May: 6.3 µg/m³Prince Albert, 29 May: 12.0 µg/m³Prince Albert, 30 May: 139.0 µg/m³, 17× its usual 8.0Prince Albert, 31 May: 103.0 µg/m³, 13× its usual 8.2Prince Albert, 1 June: 78.1 µg/m³, 9.8× its usual 8.0Prince Albert, 2 June: 10.9 µg/m³Prince Albert, 3 June: 9.6 µg/m³Prince Albert, 4 June: 52.5 µg/m³Grand CentreGrand Centre, 27 May: 12.6 µg/m³Grand Centre, 28 May: 9.3 µg/m³Grand Centre, 29 May: 9.7 µg/m³Grand Centre, 30 May: 120.0 µg/m³, 23× its usual 5.3Grand Centre, 31 May: 80.1 µg/m³, 15× its usual 5.3Grand Centre, 1 June: 46.7 µg/m³, 8.5× its usual 5.5Grand Centre, 2 June: 17.2 µg/m³Grand Centre, 3 June: 24.3 µg/m³Grand Centre, 4 June: 18.5 µg/m³Flin FlonFlin Flon, 27 May: 8.5 µg/m³Flin Flon, 28 May: 117.0 µg/m³Flin Flon, 29 May: 269.0 µg/m³Flin Flon, 30 May: 103.0 µg/m³, 21× its usual 4.1Flin Flon, 31 May: no readingFlin Flon, 1 June: 209.0 µg/m³, 42× its usual 4.2Flin Flon, 2 June: 166.0 µg/m³Flin Flon, 3 June: 211.0 µg/m³Flin Flon, 4 June: 60.6 µg/m³EstevanEstevan, 27 May: 7.6 µg/m³Estevan, 28 May: 8.1 µg/m³Estevan, 29 May: 10.0 µg/m³Estevan, 30 May: 101.0 µg/m³, 15× its usual 6.8Estevan, 31 May: 217.0 µg/m³, 32× its usual 6.8Estevan, 1 June: 93.8 µg/m³, 15× its usual 6.4Estevan, 2 June: 24.0 µg/m³Estevan, 3 June: 18.3 µg/m³Estevan, 4 June: 25.6 µg/m³St. AlbertSt. Albert, 27 May: 5.6 µg/m³St. Albert, 28 May: 17.5 µg/m³St. Albert, 29 May: 35.4 µg/m³St. Albert, 30 May: 86.5 µg/m³, 14× its usual 6.2St. Albert, 31 May: 17.7 µg/m³St. Albert, 1 June: 10.0 µg/m³St. Albert, 2 June: 14.2 µg/m³St. Albert, 3 June: 20.1 µg/m³St. Albert, 4 June: 15.9 µg/m³SaskatoonSaskatoon, 27 May: 3.9 µg/m³Saskatoon, 28 May: 6.6 µg/m³Saskatoon, 29 May: 5.9 µg/m³Saskatoon, 30 May: 78.9 µg/m³, 11× its usual 7.2Saskatoon, 31 May: 116.0 µg/m³, 16× its usual 7.2Saskatoon, 1 June: 39.3 µg/m³, 5.5× its usual 7.1Saskatoon, 2 June: 16.8 µg/m³Saskatoon, 3 June: 20.6 µg/m³Saskatoon, 4 June: 14.9 µg/m³ReginaRegina, 27 May: 5.3 µg/m³Regina, 28 May: 3.8 µg/m³Regina, 29 May: 5.5 µg/m³Regina, 30 May: 75.6 µg/m³, 14× its usual 5.6Regina, 31 May: 169.0 µg/m³, 32× its usual 5.3Regina, 1 June: 47.6 µg/m³, 9.0× its usual 5.3Regina, 2 June: 28.5 µg/m³Regina, 3 June: 20.5 µg/m³Regina, 4 June: 19.9 µg/m³Fort SaskatchewanFort Saskatchewan, 27 May: 7.6 µg/m³Fort Saskatchewan, 28 May: 12.9 µg/m³Fort Saskatchewan, 29 May: 12.5 µg/m³Fort Saskatchewan, 30 May: 37.7 µg/m³, 5.8× its usual 6.5Fort Saskatchewan, 31 May: no readingFort Saskatchewan, 1 June: 14.0 µg/m³Fort Saskatchewan, 2 June: 16.4 µg/m³Fort Saskatchewan, 3 June: 18.2 µg/m³Fort Saskatchewan, 4 June: 27.8 µg/m³27 May282930311 Jun234
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.
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

Every city it reached

CityDaysHighestUsualAbove usual
Fort McMurrayAlberta, Canada3 262.030 May5.548×
Flin FlonManitoba, Canada2 209.01 June4.242×
EstevanSaskatchewan, Canada3 217.031 May6.832×
ReginaSaskatchewan, Canada3 169.031 May5.332×
Grand CentreAlberta, Canada3 120.030 May5.323×
Prince AlbertSaskatchewan, Canada3 139.030 May8.017×
SaskatoonSaskatchewan, Canada3 116.031 May7.216×
St. AlbertAlberta, Canada1 86.530 May6.214×
Fort SaskatchewanAlberta, Canada1 37.730 May6.55.8×

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 39 of 43 episodes in Canada since our records began, by cities reached.

Bars: cities reached; colour: the level of the episode's highest daily reading. All 43.

Use this page

SmogRank, Alberta, Saskatchewan and Manitoba, Canada, May and June 2025: 9 cities with PM2.5 at twice their usual or more, 30 May to 1 June 2025, smogrank.com/episodes/2025-05-alberta-saskatchewan-and-manitoba-canada (accessed 5 October 2026).

Download top 10 (PNG)

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.