SmogRank / Episodes / Canada

Alberta and Saskatchewan, Canada, August 2023

For 3 days, from 27 to 29 August 2023, 9 cities in Canada had PM2.5 at least twice their usual for the time of year. The worst reading was Prince Albert, Saskatchewan, Canada: 88.3 µg/m³ on 29 August, about 8.2× its usual 10.8.

No cause namedWe have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached9in 1 country
Days327 to 29 August 2023
Worst day28 August9 cities counted
Furthest above usual8.2×Saskatoon

Day by day

28 August 9 cities at twice their usual or more
LethbridgeAirdrieCalgaryCranbrookRed DeerSt. AlbertMedicine HatSherwood ParkSaskatoonEdmontonSwift CurrentReginaPrince Albert
24 Aug252627282930311 Sep
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

EdmontonEdmonton, 24 August: 46.6 µg/m³, 3.6× usualEdmonton, 25 August: 79.4 µg/m³, 6.1× usualEdmonton, 26 August: 25.5 µg/m³, 2.0× usualEdmonton, 27 August: 56.6 µg/m³, 4.4× usualEdmonton, 28 August: 61.9 µg/m³, 4.8× usualEdmonton, 29 August: 46.6 µg/m³, 3.6× usualEdmonton, 30 August: 47.0 µg/m³, 3.6× usualEdmonton, 31 August: 51.9 µg/m³, 4.0× usualEdmonton, 1 September: 76.3 µg/m³, 5.9× usualSt. AlbertSt. Albert, 24 August: 39.4 µg/m³, 4.5× usualSt. Albert, 25 August: 50.1 µg/m³, 5.7× usualSt. Albert, 26 August: 13.5 µg/m³, 1.5× usualSt. Albert, 27 August: 28.7 µg/m³, 3.3× usualSt. Albert, 28 August: 30.1 µg/m³, 3.4× usualSt. Albert, 29 August: 23.1 µg/m³, 2.6× usualSt. Albert, 30 August: 23.8 µg/m³, 2.7× usualSt. Albert, 31 August: 28.4 µg/m³, 3.2× usualSt. Albert, 1 September: 45.4 µg/m³, 5.2× usualSherwood ParkSherwood Park, 24 August: 22.5 µg/m³, 2.6× usualSherwood Park, 25 August: 44.3 µg/m³, 5.2× usualSherwood Park, 26 August: 10.4 µg/m³, 1.2× usualSherwood Park, 27 August: 28.5 µg/m³, 3.4× usualSherwood Park, 28 August: 30.5 µg/m³, 3.6× usualSherwood Park, 29 August: 21.0 µg/m³, 2.5× usualSherwood Park, 30 August: 20.8 µg/m³, 2.4× usualSherwood Park, 31 August: 26.4 µg/m³, 3.1× usualSherwood Park, 1 September: 47.1 µg/m³, 5.5× usualRed DeerRed Deer, 24 August: 14.8 µg/m³, 1.4× usualRed Deer, 25 August: 25.9 µg/m³, 2.5× usualRed Deer, 26 August: 15.1 µg/m³, 1.5× usualRed Deer, 27 August: 29.8 µg/m³, 2.9× usualRed Deer, 28 August: 33.7 µg/m³, 3.3× usualRed Deer, 29 August: 28.6 µg/m³, 2.8× usualRed Deer, 30 August: 27.5 µg/m³, 2.7× usualRed Deer, 31 August: 44.0 µg/m³, 4.3× usualRed Deer, 1 September: 40.3 µg/m³, 3.9× usualPrince AlbertPrince Albert, 24 August: 5.5 µg/m³, 0.5× usualPrince Albert, 25 August: 19.3 µg/m³, 1.8× usualPrince Albert, 26 August: 16.2 µg/m³, 1.5× usualPrince Albert, 27 August: 46.2 µg/m³, 4.3× usualPrince Albert, 28 August: 64.8 µg/m³, 6.0× usualPrince Albert, 29 August: 88.3 µg/m³, 8.2× usualPrince Albert, 30 August: 52.7 µg/m³, 4.9× usualPrince Albert, 31 August: 20.2 µg/m³, 1.9× usualPrince Albert, 1 September: 98.1 µg/m³, 9.1× usualSaskatoonSaskatoon, 24 August: 11.2 µg/m³, 1.0× usualSaskatoon, 25 August: 12.9 µg/m³, 1.2× usualSaskatoon, 26 August: 12.8 µg/m³, 1.2× usualSaskatoon, 27 August: 33.1 µg/m³, 3.0× usualSaskatoon, 28 August: 48.0 µg/m³, 4.4× usualSaskatoon, 29 August: 48.9 µg/m³, 4.5× usualSaskatoon, 30 August: 55.8 µg/m³, 5.1× usualSaskatoon, 31 August: 18.5 µg/m³, 1.7× usualSaskatoon, 1 September: 113.0 µg/m³, 10× usualReginaRegina, 24 August: 19.4 µg/m³, 1.9× usualRegina, 25 August: 17.0 µg/m³, 1.7× usualRegina, 26 August: 17.9 µg/m³, 1.8× usualRegina, 27 August: 31.8 µg/m³, 3.1× usualRegina, 28 August: 74.1 µg/m³, 7.3× usualRegina, 29 August: 68.8 µg/m³, 6.7× usualRegina, 30 August: 60.0 µg/m³, 5.9× usualRegina, 31 August: 10.8 µg/m³, 1.1× usualRegina, 1 September: 59.9 µg/m³, 5.9× usualSwift CurrentSwift Current, 24 August: 12.7 µg/m³, 1.5× usualSwift Current, 25 August: 7.4 µg/m³, 0.9× usualSwift Current, 26 August: 10.9 µg/m³, 1.3× usualSwift Current, 27 August: 25.5 µg/m³, 3.1× usualSwift Current, 28 August: 52.2 µg/m³, 6.4× usualSwift Current, 29 August: 49.2 µg/m³, 6.0× usualSwift Current, 30 August: 21.0 µg/m³, 2.6× usualSwift Current, 31 August: 11.6 µg/m³, 1.4× usualSwift Current, 1 September: 46.8 µg/m³, 5.7× usualMedicine HatMedicine Hat, 24 August: 4.8 µg/m³, 0.6× usualMedicine Hat, 25 August: 11.9 µg/m³, 1.5× usualMedicine Hat, 26 August: 7.3 µg/m³, 0.9× usualMedicine Hat, 27 August: 19.7 µg/m³, 2.4× usualMedicine Hat, 28 August: 29.0 µg/m³, 3.5× usualMedicine Hat, 29 August: 21.0 µg/m³, 2.6× usualMedicine Hat, 30 August: 1.7 µg/m³, 0.2× usualMedicine Hat, 31 August: 21.5 µg/m³, 2.6× usualMedicine Hat, 1 September: 15.0 µg/m³, 1.8× usual24 Aug252627282930311 Sep
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
SaskatoonSaskatchewan, Canada3 113.01 September10.910×
Prince AlbertSaskatchewan, Canada3 98.11 September10.89.1×
ReginaSaskatchewan, Canada3 74.128 August10.27.3×
Swift CurrentSaskatchewan, Canada3 52.228 August8.26.4×
EdmontonAlberta, Canada2 79.425 August13.06.1×
St. AlbertAlberta, Canada2 50.125 August8.85.7×
Sherwood ParkAlberta, Canada2 47.11 September8.55.5×
Red DeerAlberta, Canada2 44.031 August10.34.3×
Medicine HatAlberta, Canada1 29.028 August8.23.5×

Daily means in µg/m³. Usual: the city's median for this time of year (its days within 21 days of the date, every year, leaving out the week around it). Above usual: its highest day against that.

Against other episodes in Canada

Number 15 of 18 episodes in Canada since our records began, by cities reached.

Bars: cities reached; colour: the level of the episode's highest daily reading. All 18.

Use this page

SmogRank, Alberta and Saskatchewan, Canada, August 2023: 9 cities with PM2.5 at twice their usual or more, 27 to 29 August 2023, smogrank.com/episodes/2023-08-alberta-and-saskatchewan-canada (accessed 2 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.