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Mackenzie County fire, 25 June 2023 Mackenzie County

Out · last detection 23 Sept 2023, 20:21 UTC

The fire started on 25 June 2023 in Mackenzie County, Canada, and satellites saw it burning for 91 days. Canada’s CWFIS (Natural Resources Canada) mapped an official burnt perimeter of 45,201 hectares from satellite imagery, spread across a single census subdivision.

It is the 21th largest in Alberta since 2016 (of 243 with a page). Number 56 in Canada in 2023, of 489.

Compare with…

Suggestions: Region 5, Unorganized · 2023

Burnt area
45,201ha
official perimeter (CWFIS)
Duration
91days
25 Jun 2023 – 23 Sept 2023
Census subdivisions hit
1
municipalities
Started on
25 Jun
2023
Heat detections
7,210
in a single hotspot: 408 MW
Danger at start
7
Low · FWI index
Average daily power
1.3GW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 25 Jun23 Sept
23 Sept 2023

How it evolved, day by day

25 Jun 2023 · 50 MW · 4 6 Jul 2023 · 598 MW · 43 7 Jul 2023 · 211 MW · 15 8 Jul 2023 · 265 MW · 42 9 Jul 2023 · 430 MW · 54 11 Jul 2023 · 35 MW · 17 12 Jul 2023 · 4,927 MW · 112 13 Jul 2023 · 2,386 MW · 225 14 Jul 2023 · 4,432 MW · 359 15 Jul 2023 · 5,947 MW · 351 16 Jul 2023 · 1,366 MW · 88 17 Jul 2023 · 547 MW · 133 18 Jul 2023 · 32 MW · 8 19 Jul 2023 · 27 MW · 9 20 Jul 2023 · 241 MW · 21 21 Jul 2023 · 1,265 MW · 182 22 Jul 2023 · 708 MW · 167 23 Jul 2023 · 139 MW · 69 24 Jul 2023 · 503 MW · 140 27 Jul 2023 · 3 MW · 1 28 Jul 2023 · 323 MW · 31 29 Jul 2023 · 465 MW · 52 30 Jul 2023 · 548 MW · 108 31 Jul 2023 · 279 MW · 140 2 Aug 2023 · 1 MW · 1 3 Aug 2023 · 4 MW · 3 4 Aug 2023 · 194 MW · 17 5 Aug 2023 · 83 MW · 24 6 Aug 2023 · 118 MW · 19 7 Aug 2023 · 725 MW · 105 8 Aug 2023 · 1,458 MW · 184 9 Aug 2023 · 31 MW · 14 13 Aug 2023 · 16,778 MW · 558 14 Aug 2023 · 1,517 MW · 367 15 Aug 2023 · 23 MW · 14 16 Aug 2023 · 68 MW · 15 17 Aug 2023 · 2,623 MW · 21 21 Aug 2023 · 3 MW · 1 22 Aug 2023 · 55 MW · 16 23 Aug 2023 · 318 MW · 41 24 Aug 2023 · 116 MW · 21 25 Aug 2023 · 3,074 MW · 150 26 Aug 2023 · 1,682 MW · 319 27 Aug 2023 · 3,260 MW · 240 28 Aug 2023 · 5,059 MW · 492 29 Aug 2023 · 380 MW · 184 30 Aug 2023 · 209 MW · 35 31 Aug 2023 · 64 MW · 11 1 Sept 2023 · 6,791 MW · 334 2 Sept 2023 · 60 MW · 19 3 Sept 2023 · 26 MW · 21 9 Sept 2023 · 6 MW · 2 10 Sept 2023 · 176 MW · 12 11 Sept 2023 · 76 MW · 14 12 Sept 2023 · 36 MW · 15 15 Sept 2023 · 278 MW · 24 16 Sept 2023 · 3,047 MW · 169 17 Sept 2023 · 307 MW · 83 18 Sept 2023 · 340 MW · 76 19 Sept 2023 · 693 MW · 135 20 Sept 2023 · 309 MW · 60 21 Sept 2023 · 2,345 MW · 123 22 Sept 2023 · 1,678 MW · 273 23 Sept 2023 · 2,305 MW · 627
25 Jun 16 Jul 28 Jul 8 Aug 13 Aug 24 Aug 3 Sept 20 Sept

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

The weather it burned in

31°high
67km/h · peak gust
21%lowest humidity

It had gone 0 days without rain (1 mm or more) when it started. Rain came after the fire: 8.0 mm on 24 Sept.

This area had burned before

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

How big is it?

10 km
It burned the equivalent of 29% of the area of London (452 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. Mackenzie County where it started
    46,601 ha reached on 25 Jun
    0.6 %

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 area< 0.1 ha
Residents< 20

Inside the perimeter there was no noticeable 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)
25 Jun 21.3 °C 33 % 28 km/h 0.2 mm Low 7
26 Jun 25.4 °C 39 % 34 km/h 8.3 mm Very low 2
27 Jun 27.8 °C 31 % 19 km/h 0.0 mm Low 8
28 Jun 31.2 °C 21 % 27 km/h 0.1 mm Moderate 20
29 Jun 26.6 °C 42 % 37 km/h 1.8 mm Low 7
30 Jun 23.5 °C 41 % 41 km/h 3.4 mm Very low 3
1 Jul 22.2 °C 33 % 32 km/h 0.8 mm Low 8
2 Jul 19.8 °C 50 % 34 km/h 6.2 mm Very low 1
3 Jul 19.2 °C 35 % 38 km/h 1.9 mm Very low 2
4 Jul 24.0 °C 28 % 30 km/h 0.0 mm Low 9
5 Jul 25.9 °C 26 % 42 km/h 0.0 mm Moderate 17
6 Jul 23.3 °C 33 % 21 km/h 0.0 mm Moderate 15
7 Jul 26.2 °C 35 % 40 km/h 0.1 mm Moderate 19
8 Jul 28.9 °C 36 % 22 km/h 0.0 mm Moderate 18
9 Jul 24.6 °C 43 % 34 km/h 0.0 mm Moderate 17
10 Jul 23.0 °C 40 % 26 km/h 0.0 mm Moderate 17
11 Jul 25.5 °C 38 % 23 km/h 0.0 mm Moderate 17
12 Jul 27.3 °C 28 % 36 km/h 0.0 mm High 22
13 Jul 25.3 °C 32 % 39 km/h 1.0 mm Moderate 17
14 Jul 25.4 °C 28 % 28 km/h 0.0 mm Moderate 19
15 Jul 24.2 °C 33 % 29 km/h 0.0 mm Moderate 21
16 Jul 25.8 °C 38 % 28 km/h 0.2 mm High 22
17 Jul 25.0 °C 47 % 38 km/h 3.8 mm Very low 4
18 Jul 18.1 °C 73 % 20 km/h 7.1 mm Very low 0
19 Jul 23.3 °C 58 % 19 km/h 2.9 mm Very low 0
20 Jul 26.2 °C 40 % 18 km/h 0.2 mm Very low 3
21 Jul 27.1 °C 41 % 21 km/h 0.4 mm Low 10
22 Jul 25.1 °C 34 % 28 km/h 0.0 mm Moderate 14
23 Jul 26.2 °C 36 % 20 km/h 0.7 mm Moderate 13
24 Jul 25.4 °C 33 % 22 km/h 0.0 mm Moderate 17
25 Jul 19.6 °C 65 % 40 km/h 10.1 mm Very low 0
26 Jul 20.7 °C 57 % 44 km/h 2.4 mm Very low 1
27 Jul 22.7 °C 39 % 20 km/h 0.0 mm Very low 3
28 Jul 25.1 °C 33 % 35 km/h 0.0 mm Moderate 11
29 Jul 26.1 °C 30 % 40 km/h 0.0 mm Moderate 16
30 Jul 25.2 °C 41 % 28 km/h 0.0 mm Moderate 16
31 Jul 19.7 °C 79 % 26 km/h 9.2 mm Very low 0
1 Aug 18.6 °C 68 % 32 km/h 6.8 mm Very low 0
2 Aug 21.0 °C 47 % 22 km/h 0.1 mm Very low 1
3 Aug 21.0 °C 48 % 19 km/h 0.3 mm Very low 2
4 Aug 23.4 °C 39 % 26 km/h 0.0 mm Low 6
5 Aug 23.0 °C 47 % 17 km/h 0.3 mm Low 6
6 Aug 22.4 °C 39 % 27 km/h 0.0 mm Low 9
7 Aug 21.9 °C 39 % 25 km/h 0.0 mm Low 10
8 Aug 24.5 °C 28 % 30 km/h 0.0 mm Moderate 14
9 Aug 18.4 °C 62 % 30 km/h 5.0 mm Very low 1
10 Aug 17.3 °C 74 % 16 km/h 2.7 mm Very low 0
11 Aug 18.4 °C 70 % 28 km/h 5.8 mm Very low 0
12 Aug 22.2 °C 46 % 27 km/h 0.3 mm Very low 1
13 Aug 27.5 °C 26 % 63 km/h 0.0 mm Moderate 15
14 Aug 23.3 °C 35 % 38 km/h 0.8 mm Low 9
15 Aug 16.1 °C 61 % 31 km/h 1.1 mm Very low 3
16 Aug 22.4 °C 37 % 49 km/h 0.1 mm Low 10
17 Aug 21.0 °C 45 % 39 km/h 4.2 mm Very low 2
18 Aug 12.6 °C 57 % 34 km/h 2.3 mm Very low 1
19 Aug 21.8 °C 41 % 38 km/h 1.9 mm Very low 2
20 Aug 23.6 °C 33 % 18 km/h 0.0 mm Low 6
21 Aug 24.2 °C 33 % 29 km/h 0.3 mm Low 11
22 Aug 24.7 °C 31 % 35 km/h 0.0 mm Moderate 14
23 Aug 21.7 °C 41 % 31 km/h 0.0 mm Moderate 13
24 Aug 23.2 °C 34 % 31 km/h 0.0 mm Moderate 15
25 Aug 26.5 °C 35 % 46 km/h 0.0 mm Moderate 19
26 Aug 22.7 °C 51 % 42 km/h 0.0 mm Moderate 16
27 Aug 27.1 °C 41 % 48 km/h 0.0 mm Moderate 18
28 Aug 30.2 °C 34 % 33 km/h 0.0 mm Moderate 18
29 Aug 28.2 °C 45 % 22 km/h 0.0 mm Moderate 17
30 Aug 24.3 °C 60 % 16 km/h 0.0 mm Moderate 12
31 Aug 23.0 °C 53 % 27 km/h 6.1 mm Very low 2
1 Sept 24.3 °C 31 % 67 km/h 0.0 mm Moderate 15
2 Sept 20.3 °C 44 % 44 km/h 0.9 mm Low 9
3 Sept 14.2 °C 56 % 36 km/h 11.0 mm Very low 0
4 Sept 13.5 °C 47 % 32 km/h 0.8 mm Very low 1
5 Sept 17.1 °C 40 % 25 km/h 0.0 mm Very low 4
6 Sept 14.4 °C 53 % 17 km/h 0.5 mm Very low 4
7 Sept 17.8 °C 48 % 32 km/h 0.1 mm Low 7
8 Sept 20.9 °C 35 % 27 km/h 0.0 mm Low 11
9 Sept 22.2 °C 31 % 17 km/h 0.0 mm Moderate 12
10 Sept 24.7 °C 27 % 28 km/h 0.0 mm Moderate 17
11 Sept 27.2 °C 32 % 35 km/h 0.0 mm Moderate 18
12 Sept 21.5 °C 35 % 26 km/h 0.0 mm Moderate 18
13 Sept 14.2 °C 75 % 26 km/h 13.3 mm Very low 0
14 Sept 17.5 °C 46 % 30 km/h 0.8 mm Very low 1
15 Sept 24.3 °C 30 % 44 km/h 0.0 mm Low 9
16 Sept 18.5 °C 33 % 45 km/h 0.0 mm Moderate 13
17 Sept 20.2 °C 37 % 30 km/h 0.0 mm Low 11
18 Sept 17.2 °C 38 % 42 km/h 0.0 mm Moderate 13
19 Sept 17.1 °C 45 % 31 km/h 0.4 mm Moderate 12
20 Sept 16.0 °C 44 % 27 km/h 0.0 mm Moderate 12
21 Sept 20.8 °C 35 % 48 km/h 0.1 mm Moderate 16
22 Sept 26.2 °C 29 % 43 km/h 0.0 mm Moderate 21
23 Sept 19.6 °C 36 % 42 km/h 0.0 mm Moderate 20
24 Sept after 14.2 °C 67 % 39 km/h 8.0 mm Very low 0

Before and after, from space

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

Before · 18 Jun 2023
After · 30 Sept 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 24 September 2023 the air beside the fire reached 1,952 µg/m³ of PM2.5. That day averaged 984: 66 times the WHO daily guideline (15).

PM2.5 peak1,952 µg/m³
Days over the guideline80 days
PM102,794 µg/m³
Optical depth23.44
232425262728293012345678910111213141516171819202122232425262728293031123456789101112131415161718192021222324252627282930311234567891011121314151617181920212223242526
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 · 7,210Every 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

Other fires nearby

All fires in Canada ›

Frequently asked questions

How long did the Mackenzie County fire last?
It burned between 25 June 2023 and 23 September 2023: 91 days, according to the dates recorded by Canada’s CWFIS and the heat detections seen by satellite.
How much area did it burn?
The official perimeter mapped by Canada’s CWFIS (Natural Resources Canada) is 45,201 hectares (452.0 km²). Other tallies, such as those of provincial agencies, may give slightly different figures.
Which census subdivisions burned?
The fire only entered Mackenzie County (46,601 ha, 0.6 %).
What was the weather like?
During the fire the temperature reached 31.2 °C, humidity dropped to 21 % and gusts hit 67 km/h. The fire danger index (FWI) reached 22, 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 from the perimeter: the VIIRS detections inside it did not change them. 7,210 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.