SmogRank / Episodes / Canada

Alberta and British Columbia, Canada, January 2023

For 3 days, from 8 to 10 January 2023, 9 cities in Canada had PM2.5 at least twice their usual for the time of year. The worst reading was Edmonton, Alberta, Canada: 76.4 µg/m³ on 10 January, about 8.3× its usual 9.2. Readings stopped after 10 January, so this episode may have run longer.

Few fires were detected near these cities on those days. Spreads like this usually come from still weather trapping smoke from heating, traffic and industry, or from dust.
Cities reached9in 1 country
Days38 to 10 January 2023
Worst day10 January8 cities counted
Furthest above usual12×Sherwood Park

Day by day

10 January 8 cities at twice their usual or more
AirdrieWilliams LakePrince GeorgeQuesnelRed DeerGrande PrairieGrand CentreEdsonEdmontonFort SaskatchewanSt. AlbertSherwood Park
5 Jan678910111213
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, 5 January: 10.1 µg/m³Edmonton, 6 January: 16.8 µg/m³Edmonton, 7 January: 15.7 µg/m³Edmonton, 8 January: 38.5 µg/m³, 4.1× its usual 9.3Edmonton, 9 January: 54.7 µg/m³, 5.9× its usual 9.3Edmonton, 10 January: 76.4 µg/m³, 8.3× its usual 9.2Edmonton, 11 January: no readingEdmonton, 12 January: no readingEdmonton, 13 January: no readingFort SaskatchewanFort Saskatchewan, 5 January: 14.9 µg/m³Fort Saskatchewan, 6 January: 16.7 µg/m³Fort Saskatchewan, 7 January: 18.9 µg/m³Fort Saskatchewan, 8 January: 33.5 µg/m³, 4.5× its usual 7.5Fort Saskatchewan, 9 January: 59.2 µg/m³, 7.7× its usual 7.7Fort Saskatchewan, 10 January: 74.6 µg/m³, 9.8× its usual 7.6Fort Saskatchewan, 11 January: no readingFort Saskatchewan, 12 January: no readingFort Saskatchewan, 13 January: no readingGrand CentreGrand Centre, 5 January: 24.0 µg/m³Grand Centre, 6 January: 6.2 µg/m³Grand Centre, 7 January: 18.2 µg/m³Grand Centre, 8 January: 26.4 µg/m³, 5.3× its usual 4.9Grand Centre, 9 January: 24.2 µg/m³Grand Centre, 10 January: 18.6 µg/m³Grand Centre, 11 January: no readingGrand Centre, 12 January: no readingGrand Centre, 13 January: no readingSt. AlbertSt. Albert, 5 January: 10.8 µg/m³St. Albert, 6 January: 16.8 µg/m³St. Albert, 7 January: 14.7 µg/m³St. Albert, 8 January: 25.8 µg/m³, 4.2× its usual 6.1St. Albert, 9 January: 39.0 µg/m³, 6.4× its usual 6.1St. Albert, 10 January: 60.5 µg/m³, 9.9× its usual 6.1St. Albert, 11 January: no readingSt. Albert, 12 January: no readingSt. Albert, 13 January: no readingSherwood ParkSherwood Park, 5 January: 3.8 µg/m³Sherwood Park, 6 January: 8.5 µg/m³Sherwood Park, 7 January: 7.6 µg/m³Sherwood Park, 8 January: 25.2 µg/m³, 4.4× its usual 5.7Sherwood Park, 9 January: 38.4 µg/m³, 6.6× its usual 5.8Sherwood Park, 10 January: 67.9 µg/m³, 12× its usual 5.8Sherwood Park, 11 January: no readingSherwood Park, 12 January: no readingSherwood Park, 13 January: no readingEdsonEdson, 5 January: no readingEdson, 6 January: 22.1 µg/m³Edson, 7 January: 22.1 µg/m³Edson, 8 January: 25.2 µg/m³, 4.3× its usual 5.9Edson, 9 January: 32.7 µg/m³, 5.5× its usual 5.9Edson, 10 January: 36.2 µg/m³, 6.2× its usual 5.8Edson, 11 January: no readingEdson, 12 January: no readingEdson, 13 January: no readingGrande PrairieGrande Prairie, 5 January: 20.9 µg/m³Grande Prairie, 6 January: 28.0 µg/m³Grande Prairie, 7 January: 20.7 µg/m³Grande Prairie, 8 January: 21.2 µg/m³Grande Prairie, 9 January: 19.5 µg/m³Grande Prairie, 10 January: 34.7 µg/m³, 5.1× its usual 6.8Grande Prairie, 11 January: no readingGrande Prairie, 12 January: no readingGrande Prairie, 13 January: no readingQuesnelQuesnel, 5 January: 8.7 µg/m³Quesnel, 6 January: 11.1 µg/m³Quesnel, 7 January: 4.7 µg/m³Quesnel, 8 January: 7.3 µg/m³Quesnel, 9 January: 14.9 µg/m³Quesnel, 10 January: 26.4 µg/m³, 3.6× its usual 7.4Quesnel, 11 January: no readingQuesnel, 12 January: no readingQuesnel, 13 January: no readingRed DeerRed Deer, 5 January: 7.9 µg/m³Red Deer, 6 January: 7.9 µg/m³Red Deer, 7 January: 6.2 µg/m³Red Deer, 8 January: 13.1 µg/m³Red Deer, 9 January: 13.5 µg/m³Red Deer, 10 January: 26.3 µg/m³, 4.0× its usual 6.5Red Deer, 11 January: no readingRed Deer, 12 January: no readingRed Deer, 13 January: no reading5 Jan678910111213
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
Sherwood ParkAlberta, Canada3 67.910 January5.812×
St. AlbertAlberta, Canada3 60.510 January6.19.9×
Fort SaskatchewanAlberta, Canada3 74.610 January7.69.8×
EdmontonAlberta, Canada3 76.410 January9.28.3×
EdsonAlberta, Canada3 36.210 January5.86.2×
Grand CentreAlberta, Canada1 26.48 January4.95.3×
Grande PrairieAlberta, Canada1 34.710 January6.85.1×
Red DeerAlberta, Canada1 26.310 January6.54.0×
QuesnelBritish Columbia, Canada1 26.410 January7.43.6×

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 42 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 and British Columbia, Canada, January 2023: 9 cities with PM2.5 at twice their usual or more, 8 to 10 January 2023, smogrank.com/episodes/2023-01-alberta-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.