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Yellowhead County fire, 2 May 2023 Yellowhead County, Clearwater County, Brazeau County

Out · last detection 23 Jul 2023, 11:32 UTC

The fire started on 2 May 2023 in Yellowhead County, Canada, and satellites saw it burning for 84 days. Canada’s CWFIS (Natural Resources Canada) mapped an official burnt perimeter of 195,934 hectares from satellite imagery, spread across 4 census subdivisions.

It is the 4th largest in Alberta since 2016 (of 243 with a page). Number 13 in Canada in 2023, of 489.

Compare with…
Burnt area
195,934ha
official perimeter (CWFIS)
Duration
84days
2 May 2023 – 24 Jul 2023
Census subdivisions hit
4
municipalities
Started on
2 May
2023
Heat detections
20,329
in a single hotspot: 1,514 MW
Danger at start
16
Moderate · FWI index
Average daily power
12.8GW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 2 May24 Jul
23 Jul 2023

How it evolved, day by day

2 May 2023 · 1 MW · 2 4 May 2023 · 3,034 MW · 33 5 May 2023 · 221,724 MW · 4673 6 May 2023 · 41,420 MW · 3858 7 May 2023 · 70 MW · 46 13 May 2023 · 578 MW · 21 14 May 2023 · 2,564 MW · 111 15 May 2023 · 7,392 MW · 454 16 May 2023 · 10,247 MW · 888 17 May 2023 · 7,065 MW · 505 18 May 2023 · 11,240 MW · 682 19 May 2023 · 29,212 MW · 807 20 May 2023 · 15,932 MW · 2250 21 May 2023 · 9,808 MW · 672 25 May 2023 · 0 MW · 1 26 May 2023 · 317 MW · 11 27 May 2023 · 78 MW · 36 28 May 2023 · 237 MW · 64 29 May 2023 · 29 MW · 12 4 Jun 2023 · 1 MW · 1 6 Jun 2023 · 632 MW · 12 7 Jun 2023 · 1,344 MW · 50 8 Jun 2023 · 7,868 MW · 457 9 Jun 2023 · 81,907 MW · 1588 10 Jun 2023 · 16,584 MW · 2765 11 Jun 2023 · 119 MW · 45 12 Jun 2023 · 1,858 MW · 164 13 Jun 2023 · 966 MW · 108 24 Jun 2023 · 1 MW · 1 27 Jun 2023 · 1 MW · 1 5 Jul 2023 · 1 MW · 1 9 Jul 2023 · 5 MW · 4 17 Jul 2023 · 1 MW · 1 19 Jul 2023 · 0 MW · 1 20 Jul 2023 · 1 MW · 1 21 Jul 2023 · 1 MW · 1 23 Jul 2023 · 8 MW · 2
2 May 5 May 14 May 20 May 29 May 10 Jun 5 Jul 23 Jul

Fire radiative power detected each day, in megawatts, and number of hotspots. The magenta bar marks the peak day.

The weather it burned in

28°high
71km/h · peak gust
13%lowest humidity

It had gone 5 days without rain (1 mm or more) when it started. Rain came after the fire: 1.4 mm on 25 Jul.

This area had burned before

No earlier perimeters overlap this fire since 2016, when the satellite record begins.

How big is it?

20 km
It burned the equivalent of 1.2 times the area of London (1,959 km² against 1,583 km²).

London boundary: geoBoundaries · Office for National Statistics (Open Government Licence v3.0).

This compares size, not location: both shapes are at the same scale, north up, centred on each other.

What happened to each census subdivision

  1. Yellowhead County where it started
    185,080 ha reached on 2 May
    8.2 %
  2. Clearwater County
    8,294 ha reached on 4 May
    0.4 %
  3. Brazeau County
    1,344 ha reached on 6 May
    0.4 %
  4. O'Chiese 203
    725 ha reached on 5 May
    5.2 %

Burnt area inside each census subdivision, from crossing the official perimeter with administrative boundaries. The distance runs from the point marking the centre of each area to the nearest fire: staying a kilometre away does not mean it reached the houses.

People and buildings inside the perimeter

GHSL 2025
Built-up area3.4 ha
Residents< 20

Inside the perimeter there were about 3.4 hectares of built-up land and almost nobody lived there (GHSL 2025, satellite-based estimate).

This is an estimate on 100 m cells, made from satellite imagery and census data: it does not mean that homes burned or that anyone was harmed. The perimeter also contains land that never burned. The GHSL 2025 epoch is a projection made from 2020 and earlier data.

Source: Global Human Settlement Layer (GHS-BUILT-S and GHS-POP R2023A), European Commission Joint Research Centre (JRC), © European Union, CC BY 4.0. Sum inside the perimeter computed by WorldFires. human-settlement.emergency.copernicus.eu

The weather day by day

ECMWF ERA5 reanalysis at the fire location, the standard reference for past weather, and the Canadian Fire Weather Index (the same system Copernicus uses), computed by WorldFires from that data. Days after the fire run until the first rain.

Open-Meteo.com (CC BY 4.0) · Copernicus Climate Change Service (ERA5)

Day High Min. humidity Peak gust Rain Danger (FWI)
2 May 22.3 °C 28 % 34 km/h 0.0 mm Moderate 16
3 May 26.3 °C 26 % 31 km/h 1.0 mm Moderate 14
4 May 27.0 °C 15 % 44 km/h 0.1 mm High 22
5 May 23.0 °C 20 % 58 km/h 0.0 mm High 28
6 May 14.8 °C 33 % 63 km/h 0.4 mm High 23
7 May 12.9 °C 52 % 38 km/h 12.1 mm Very low 0
8 May 11.6 °C 62 % 25 km/h 6.9 mm Very low 0
9 May 13.4 °C 50 % 24 km/h 6.8 mm Very low 0
10 May 15.3 °C 54 % 24 km/h 4.8 mm Very low 0
11 May 16.7 °C 43 % 28 km/h 3.7 mm Very low 0
12 May 22.3 °C 24 % 23 km/h 0.0 mm Very low 2
13 May 26.4 °C 18 % 28 km/h 0.0 mm Low 11
14 May 26.9 °C 14 % 37 km/h 0.0 mm Moderate 17
15 May 28.0 °C 20 % 23 km/h 0.0 mm Moderate 17
16 May 19.2 °C 27 % 39 km/h 0.0 mm Moderate 17
17 May 19.4 °C 24 % 27 km/h 0.0 mm Moderate 16
18 May 20.0 °C 30 % 38 km/h 0.0 mm Moderate 17
19 May 25.3 °C 22 % 48 km/h 0.0 mm Moderate 20
20 May 24.1 °C 29 % 31 km/h 1.2 mm Low 11
21 May 24.4 °C 30 % 24 km/h 4.6 mm Very low 3
22 May 14.3 °C 77 % 43 km/h 24.4 mm Very low 0
23 May 9.8 °C 63 % 48 km/h 9.6 mm Very low 0
24 May 16.3 °C 41 % 37 km/h 0.1 mm Very low 0
25 May 17.7 °C 38 % 25 km/h 0.0 mm Very low 1
26 May 21.5 °C 31 % 31 km/h 0.3 mm Low 6
27 May 23.8 °C 24 % 25 km/h 0.0 mm Low 11
28 May 22.3 °C 33 % 36 km/h 2.9 mm Very low 2
29 May 20.8 °C 30 % 32 km/h 0.3 mm Low 6
30 May 20.8 °C 33 % 31 km/h 1.4 mm Very low 5
31 May 14.6 °C 65 % 37 km/h 12.2 mm Very low 0
1 Jun 13.2 °C 52 % 26 km/h 7.6 mm Very low 0
2 Jun 21.0 °C 36 % 40 km/h 0.2 mm Very low 1
3 Jun 23.9 °C 36 % 39 km/h 0.1 mm Low 6
4 Jun 26.9 °C 30 % 35 km/h 2.9 mm Very low 4
5 Jun 16.8 °C 52 % 43 km/h 2.0 mm Very low 2
6 Jun 21.6 °C 27 % 34 km/h 0.0 mm Low 6
7 Jun 27.1 °C 13 % 23 km/h 0.0 mm Moderate 17
8 Jun 28.0 °C 27 % 40 km/h 0.0 mm Moderate 19
9 Jun 28.1 °C 23 % 56 km/h 0.0 mm High 24
10 Jun 27.1 °C 37 % 47 km/h 0.6 mm Moderate 18
11 Jun 21.9 °C 44 % 34 km/h 0.0 mm Moderate 14
12 Jun 26.7 °C 25 % 22 km/h 0.0 mm Moderate 17
13 Jun 26.2 °C 30 % 40 km/h 2.1 mm Low 9
14 Jun 10.4 °C 94 % 53 km/h 30.4 mm Very low 0
15 Jun 16.7 °C 39 % 56 km/h 3.1 mm Very low 0
16 Jun 19.1 °C 43 % 38 km/h 0.8 mm Very low 2
17 Jun 13.4 °C 62 % 31 km/h 11.1 mm Very low 0
18 Jun 7.6 °C 91 % 49 km/h 60.0 mm Very low 0
19 Jun 6.9 °C 98 % 60 km/h 75.4 mm Very low 0
20 Jun 14.0 °C 41 % 46 km/h 15.1 mm Very low 0
21 Jun 16.0 °C 41 % 35 km/h 0.9 mm Very low 0
22 Jun 20.5 °C 27 % 20 km/h 1.4 mm Very low 1
23 Jun 20.6 °C 40 % 26 km/h 4.4 mm Very low 0
24 Jun 23.8 °C 33 % 21 km/h 1.0 mm Very low 1
25 Jun 19.6 °C 58 % 31 km/h 2.6 mm Very low 1
26 Jun 24.9 °C 34 % 24 km/h 0.0 mm Very low 3
27 Jun 24.6 °C 34 % 24 km/h 0.9 mm Very low 5
28 Jun 25.4 °C 40 % 22 km/h 1.5 mm Very low 3
29 Jun 23.8 °C 45 % 27 km/h 0.6 mm Low 6
30 Jun 23.6 °C 47 % 24 km/h 11.7 mm Very low 0
1 Jul 15.3 °C 70 % 41 km/h 12.9 mm Very low 0
2 Jul 15.2 °C 50 % 71 km/h 2.5 mm Very low 1
3 Jul 12.6 °C 61 % 48 km/h 5.9 mm Very low 0
4 Jul 19.1 °C 48 % 29 km/h 1.1 mm Very low 0
5 Jul 23.5 °C 33 % 35 km/h 0.0 mm Very low 3
6 Jul 22.2 °C 44 % 23 km/h 5.5 mm Very low 0
7 Jul 23.0 °C 45 % 30 km/h 0.1 mm Very low 2
8 Jul 26.5 °C 34 % 19 km/h 0.0 mm Low 6
9 Jul 27.8 °C 35 % 20 km/h 3.0 mm Very low 2
10 Jul 23.3 °C 55 % 34 km/h 13.2 mm Very low 0
11 Jul 20.0 °C 69 % 22 km/h 15.4 mm Very low 0
12 Jul 22.0 °C 43 % 31 km/h 1.4 mm Very low 0
13 Jul 19.7 °C 61 % 41 km/h 4.4 mm Very low 0
14 Jul 21.7 °C 49 % 32 km/h 1.1 mm Very low 1
15 Jul 23.3 °C 49 % 30 km/h 7.9 mm Very low 0
16 Jul 23.5 °C 50 % 25 km/h 3.7 mm Very low 0
17 Jul 15.4 °C 78 % 30 km/h 3.9 mm Very low 0
18 Jul 21.0 °C 37 % 55 km/h 0.0 mm Very low 1
19 Jul 22.8 °C 38 % 20 km/h 0.0 mm Very low 3
20 Jul 24.4 °C 44 % 23 km/h 0.5 mm Very low 5
21 Jul 25.2 °C 51 % 31 km/h 1.4 mm Very low 2
22 Jul 25.4 °C 47 % 22 km/h 3.6 mm Very low 1
23 Jul 22.8 °C 57 % 31 km/h 0.8 mm Very low 2
24 Jul 24.3 °C 64 % 34 km/h 9.5 mm Very low 0
25 Jul after 18.9 °C 36 % 52 km/h 1.4 mm Very low 1

Before and after, from space

Drag the line to compare the same ground before the fire and after it.

Before · 25 Apr 2023
After · 31 Jul 2023

If the day is cloudy, change the date: each satellite passes once a day. In false colour the burnt ground looks brown or red.

The smoke

CAMS · Copernicus

On 8 May 2023 the air beside the fire reached 566 µg/m³ of PM2.5. That day averaged 279: 19 times the WHO daily guideline (15).

PM2.5 peak566 µg/m³
Days over the guideline60 days
PM10808 µg/m³
Optical depth3.52
2345678910111213141516171819202122232425262728293031123456789101112131415161718192021222324252627282930123456789101112131415161718192021222324252627
Good Fair Moderate Poor Very poor Extremely poor

Particles from the Copernicus CAMS model at the centre of the perimeter; these are not measurements in each town. The pale bar is the worst hour, the solid one the daily average.

Open-Meteo.com (CC BY 4.0) · Copernicus Atmosphere Monitoring Service (CAMS)

Detections table · 20,329Every satellite heat detection, one by one, with time, satellite, power and coordinates.
⬇ Download CSV Times in UTC. Each detection is a 375 m pixel: a large fire yields hundreds per pass.
Date and timeSatelliteFRP (MW)LatLon

Frequently asked questions

How long did the Yellowhead County fire last?
According to the heat detections seen by satellite inside the perimeter, it burned from 2 May 2023 to 24 July 2023 (84 days). The perimeter dates it from 4 May 2023 to 24 July 2023.
How much area did it burn?
The official perimeter mapped by Canada’s CWFIS (Natural Resources Canada) is 195,934 hectares (1,959.3 km²). Other tallies, such as those of provincial agencies, may give slightly different figures.
Which census subdivisions burned?
The fire entered 4 census subdivisions: Yellowhead County (185,080 ha, 8.2 %); Clearwater County (8,294 ha, 0.4 %); Brazeau County (1,344 ha, 0.4 %); O'Chiese 203 (725 ha, 5.2 %).
What was the weather like?
During the fire the temperature reached 28.1 °C, humidity dropped to 13 % and gusts hit 71 km/h. The fire danger index (FWI) reached 28, class High.
Where does this data come from?
From the official burnt perimeter of Canada’s CWFIS (NBAC, Natural Resources Canada) or, for the current season and until NBAC publishes it, the one rebuilt by GWIS (Copernicus); from NASA FIRMS VIIRS hotspots; and from the administrative boundaries of Canada. It is not an official report.

Where to verify it

A satellite detection is not an official report. Final figures and the fire’s status are published by each country’s emergency service.

Emergency number: 911 · Emergency number and official warnings ›

Satellite cross-check

History of this page Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.

No changes since 24 October 2026.

RSS Changes to this page

Does something look wrong on this page?

This page is built from satellite data and official records, and it sometimes gets things wrong: the wrong dates, the wrong town, two fires merged into one, or something that was not a wildfire at all. If you know this fire first-hand (you live nearby, saw it, fought it or reported on it), tell us what really happened and we will check it.

Report an error
What do you think is wrong?

We will only use your email to reply about this report. Privacy. This is not an emergency service: if there is a fire now, call 911.

How we know this
  • Perimeter: NBAC (Natural Resources Canada), official.
  • Dates adjusted with the VIIRS detections inside the perimeter, which said 4 May 2023 to 24 July 2023. 20,329 Suomi-NPP VIIRS detections on those dates.
  • We have not matched this page with any official record.
  • Weather: Copernicus ERA5 reanalysis at the fire location, in cells of about 25 km.
  • Built-up area and population come from the JRC Global Human Settlement Layer (epoch 2025, 100 m cells), summed inside the perimeter: an estimate of what was there, not a damage count.

How we build fire pages: methodology ›

Where this data comes from

The perimeter is official: it comes from the National Burned Area Composite (NBAC) of the Canadian Wildland Fire Information System (CWFIS), Natural Resources Canada, which maps it on satellite imagery and publishes it under the Open Government Licence – Canada. Until NBAC publishes the current season, this year’s fires carry the perimeter rebuilt from heat detections by GWIS (Copernicus, CC BY 4.0), which is approximate. Heat detections come from the VIIRS sensors aboard Suomi-NPP and NOAA-20, distributed by NASA FIRMS at 375 m resolution. Census subdivision boundaries come from geoBoundaries ADM3 (Open Data Commons Open Database License 1.0). The area per census subdivision is computed by WorldFires by crossing the perimeter with those boundaries, so it may differ slightly from official figures.