How long did the Mackenzie County fire last?

It burned between 23 June 2023 and 24 November 2023: 155 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 29,574 hectares (295.7 km²). Other tallies, such as those of provincial agencies, may give slightly different figures.

Which census subdivisions burned?

The fire only entered Mackenzie County (28,775 ha, 0.4 %).

What was the weather like?

During the fire the temperature reached 27.6 °C, humidity dropped to 22 % and gusts hit 64 km/h. The fire danger index (FWI) reached 20, class Moderate.

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.

CA · Canada · 2023-06-23 → 2023-11-24

Mackenzie County fire, 23 June 2023 Mackenzie County

Out · last detection 24 Nov 2023, 20:58 UTC

The fire started on 23 June 2023 in Mackenzie County, Canada, and satellites saw it burning for 155 days. Canada’s CWFIS (Natural Resources Canada) mapped an official burnt perimeter of 29,574 hectares from satellite imagery, spread across a single census subdivision.

It is the 31th largest in Alberta since 2016 (of 243 with a page). Number 76 in Canada in 2023, of 489.

Compare with…

Suggestions: Mackenzie County · 2024

Burnt area: 29,574ha; official perimeter (CWFIS)
Duration: 155days; 23 Jun 2023 – 24 Nov 2023
Census subdivisions hit: 1; municipalities
Started on: 23 Jun; 2023
Heat detections: 4,454; in a single hotspot: 430 MW
Danger at start: 3; Very low · FWI index
Average daily power: 1.9GW; detected power per day, on average

HOTSPOTS BY DAY 23 Jun24 Nov

Play back 24 Nov 2023

How it evolved, day by day

24 Jun 29 Jun 30 Jun 5 Jul 9 Jul 13 Jul 17 Jul 23 Nov

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

64km/h · peak gust

22%lowest humidity

It had gone 0 days without rain (1 mm or more) when it started. Rain came after the fire: 1.8 mm on 29 Nov.

This area had burned before

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

How big is it?

It burned the equivalent of 19% of the area of London (296 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

Mackenzie County where it started

28,775 ha reached on 24 Jun

0.4 %

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)
23 Jun	25.3 °C	32 %	16 km/h	0.2 mm	Very low 3
24 Jun	24.8 °C	43 %	38 km/h	3.5 mm	Very low 1
25 Jun	19.3 °C	45 %	30 km/h	0.3 mm	Very low 4
26 Jun	22.9 °C	45 %	40 km/h	1.8 mm	Very low 2
27 Jun	25.4 °C	35 %	18 km/h	0.0 mm	Low 7
28 Jun	25.5 °C	48 %	22 km/h	1.2 mm	Very low 5
29 Jun	24.0 °C	42 %	43 km/h	0.4 mm	Low 10
30 Jun	22.7 °C	28 %	54 km/h	0.7 mm	Moderate 16
1 Jul	20.7 °C	31 %	27 km/h	3.4 mm	Very low 2
2 Jul	17.4 °C	53 %	48 km/h	15.7 mm	Very low 0
3 Jul	17.6 °C	56 %	46 km/h	4.2 mm	Very low 0
4 Jul	21.7 °C	32 %	23 km/h	0.0 mm	Very low 1
5 Jul	24.7 °C	40 %	44 km/h	1.0 mm	Very low 5
6 Jul	22.1 °C	31 %	28 km/h	0.0 mm	Low 9
7 Jul	24.2 °C	31 %	23 km/h	0.0 mm	Low 11
8 Jul	27.1 °C	36 %	29 km/h	0.1 mm	Moderate 13
9 Jul	24.3 °C	50 %	36 km/h	0.0 mm	Moderate 13
10 Jul	20.2 °C	53 %	37 km/h	2.1 mm	Very low 3
11 Jul	23.7 °C	53 %	23 km/h	8.4 mm	Very low 0
12 Jul	24.5 °C	55 %	28 km/h	1.8 mm	Very low 1
13 Jul	23.2 °C	40 %	39 km/h	0.2 mm	Low 6
14 Jul	21.3 °C	41 %	32 km/h	0.0 mm	Low 8
15 Jul	22.7 °C	39 %	32 km/h	0.0 mm	Low 10
16 Jul	21.4 °C	61 %	28 km/h	8.9 mm	Very low 0
17 Jul	15.9 °C	83 %	31 km/h	7.1 mm	Very low 0
18 Jul	19.6 °C	59 %	17 km/h	1.4 mm	Very low 0
19 Jul	20.5 °C	65 %	23 km/h	8.2 mm	Very low 0
20 Jul	23.7 °C	52 %	23 km/h	0.6 mm	Very low 0
21 Jul	25.1 °C	41 %	18 km/h	0.1 mm	Very low 2
22 Jul	24.0 °C	47 %	27 km/h	0.9 mm	Very low 4
23 Jul	24.9 °C	29 %	25 km/h	0.2 mm	Low 9
24 Jul	22.4 °C	50 %	28 km/h	5.5 mm	Very low 1
25 Jul	15.5 °C	95 %	34 km/h	37.6 mm	Very low 0
26 Jul	15.8 °C	72 %	37 km/h	2.0 mm	Very low 0
27 Jul	18.9 °C	44 %	32 km/h	0.0 mm	Very low 0
28 Jul	21.8 °C	39 %	22 km/h	0.1 mm	Very low 1
29 Jul	23.6 °C	36 %	30 km/h	0.0 mm	Low 6
30 Jul	24.4 °C	40 %	20 km/h	0.0 mm	Low 8
31 Jul	17.1 °C	61 %	25 km/h	5.1 mm	Very low 0
1 Aug	17.6 °C	76 %	31 km/h	11.2 mm	Very low 0
2 Aug	18.1 °C	63 %	20 km/h	10.2 mm	Very low 0
3 Aug	15.1 °C	78 %	24 km/h	19.3 mm	Very low 0
4 Aug	20.0 °C	54 %	27 km/h	0.5 mm	Very low 0
5 Aug	23.2 °C	44 %	25 km/h	0.0 mm	Very low 0
6 Aug	21.8 °C	55 %	24 km/h	2.1 mm	Very low 0
7 Aug	20.9 °C	40 %	35 km/h	0.0 mm	Very low 3
8 Aug	19.6 °C	50 %	41 km/h	0.2 mm	Very low 4
9 Aug	16.4 °C	82 %	34 km/h	14.8 mm	Very low 0
10 Aug	14.6 °C	90 %	19 km/h	16.4 mm	Very low 0
11 Aug	17.6 °C	69 %	35 km/h	8.3 mm	Very low 0
12 Aug	20.5 °C	48 %	40 km/h	1.0 mm	Very low 0
13 Aug	26.3 °C	41 %	41 km/h	0.0 mm	Very low 2
14 Aug	20.4 °C	35 %	50 km/h	0.0 mm	Low 7
15 Aug	19.0 °C	58 %	41 km/h	6.1 mm	Very low 0
16 Aug	21.1 °C	47 %	45 km/h	0.4 mm	Very low 1
17 Aug	18.4 °C	45 %	32 km/h	1.2 mm	Very low 1
18 Aug	10.6 °C	64 %	37 km/h	6.7 mm	Very low 0
19 Aug	19.6 °C	43 %	35 km/h	0.2 mm	Very low 1
20 Aug	22.1 °C	35 %	21 km/h	0.2 mm	Very low 3
21 Aug	22.8 °C	31 %	21 km/h	0.0 mm	Low 7
22 Aug	21.9 °C	40 %	20 km/h	0.0 mm	Low 8
23 Aug	17.5 °C	66 %	23 km/h	0.4 mm	Very low 5
24 Aug	19.4 °C	46 %	22 km/h	0.0 mm	Low 6
25 Aug	23.7 °C	39 %	38 km/h	0.0 mm	Low 10
26 Aug	23.9 °C	46 %	38 km/h	0.0 mm	Low 11
27 Aug	24.7 °C	45 %	28 km/h	0.0 mm	Low 10
28 Aug	27.6 °C	42 %	21 km/h	0.0 mm	Low 10
29 Aug	27.6 °C	33 %	22 km/h	0.0 mm	Moderate 13
30 Aug	23.4 °C	52 %	18 km/h	1.5 mm	Very low 5
31 Aug	21.0 °C	52 %	37 km/h	0.0 mm	Low 8
1 Sept	23.4 °C	34 %	59 km/h	0.0 mm	Moderate 18
2 Sept	18.0 °C	37 %	56 km/h	0.0 mm	Moderate 18
3 Sept	12.3 °C	53 %	48 km/h	1.6 mm	Very low 5
4 Sept	12.7 °C	46 %	35 km/h	0.8 mm	Low 6
5 Sept	12.5 °C	50 %	35 km/h	0.1 mm	Low 7
6 Sept	11.1 °C	69 %	25 km/h	1.6 mm	Very low 2
7 Sept	16.9 °C	45 %	29 km/h	0.0 mm	Very low 4
8 Sept	18.9 °C	33 %	23 km/h	0.0 mm	Low 8
9 Sept	20.8 °C	29 %	17 km/h	0.0 mm	Moderate 13
10 Sept	23.5 °C	32 %	34 km/h	0.0 mm	Moderate 17
11 Sept	25.5 °C	30 %	31 km/h	0.0 mm	Moderate 19
12 Sept	19.1 °C	41 %	24 km/h	0.0 mm	Moderate 17
13 Sept	15.3 °C	53 %	53 km/h	6.2 mm	Very low 1
14 Sept	16.9 °C	31 %	41 km/h	0.1 mm	Low 6
15 Sept	24.3 °C	22 %	48 km/h	0.0 mm	Moderate 19
16 Sept	18.0 °C	34 %	45 km/h	0.0 mm	Moderate 18
17 Sept	18.6 °C	36 %	35 km/h	0.0 mm	Moderate 16
18 Sept	15.0 °C	40 %	47 km/h	1.1 mm	Low 9
19 Sept	15.3 °C	44 %	29 km/h	0.6 mm	Low 10
20 Sept	14.7 °C	52 %	22 km/h	0.5 mm	Low 9
21 Sept	18.0 °C	40 %	52 km/h	0.0 mm	Moderate 16
22 Sept	24.3 °C	30 %	40 km/h	0.0 mm	Moderate 20
23 Sept	18.8 °C	48 %	35 km/h	0.0 mm	Moderate 17
24 Sept	14.1 °C	58 %	40 km/h	1.6 mm	Very low 5
25 Sept	13.2 °C	58 %	47 km/h	0.0 mm	Low 8
26 Sept	17.6 °C	44 %	46 km/h	3.8 mm	Very low 4
27 Sept	14.7 °C	54 %	28 km/h	0.1 mm	Very low 4
28 Sept	7.4 °C	90 %	21 km/h	1.7 mm	Very low 1
29 Sept	6.6 °C	75 %	23 km/h	0.0 mm	Very low 1
30 Sept	9.6 °C	66 %	26 km/h	0.5 mm	Very low 3
1 Oct	11.7 °C	49 %	42 km/h	0.6 mm	Low 5
2 Oct	12.3 °C	57 %	28 km/h	1.4 mm	Very low 3
3 Oct	13.4 °C	43 %	32 km/h	0.8 mm	Very low 5
4 Oct	6.4 °C	86 %	54 km/h	9.7 mm	Very low 0
5 Oct	1.9 °C	41 %	46 km/h	0.0 mm	Very low 0
6 Oct	11.9 °C	48 %	36 km/h	0.0 mm	Very low 2
7 Oct	18.1 °C	47 %	26 km/h	0.0 mm	Very low 4
8 Oct	23.1 °C	24 %	36 km/h	0.0 mm	Moderate 13
9 Oct	22.3 °C	33 %	31 km/h	0.0 mm	Moderate 14
10 Oct	17.7 °C	44 %	29 km/h	0.0 mm	Moderate 13
11 Oct	15.7 °C	60 %	24 km/h	1.5 mm	Very low 3
12 Oct	13.5 °C	67 %	28 km/h	0.3 mm	Very low 4
13 Oct	12.3 °C	55 %	42 km/h	0.0 mm	Low 7
14 Oct	11.7 °C	60 %	41 km/h	0.0 mm	Low 7
15 Oct	12.8 °C	55 %	28 km/h	0.0 mm	Low 7
16 Oct	14.9 °C	43 %	21 km/h	0.0 mm	Low 8
17 Oct	7.7 °C	71 %	21 km/h	0.3 mm	Low 6
18 Oct	12.8 °C	56 %	46 km/h	1.0 mm	Low 6
19 Oct	13.8 °C	41 %	42 km/h	0.0 mm	Low 9
20 Oct	9.5 °C	37 %	45 km/h	0.0 mm	Low 11
21 Oct	-0.7 °C	59 %	31 km/h	2.3 mm	Very low 2
22 Oct	-5.4 °C	53 %	24 km/h	0.0 mm	Very low 2
23 Oct	-6.9 °C	50 %	44 km/h	0.0 mm	Very low 4
24 Oct	-6.0 °C	52 %	38 km/h	0.0 mm	Very low 4
25 Oct	-6.8 °C	56 %	32 km/h	0.6 mm	Very low 4
26 Oct	-3.3 °C	71 %	40 km/h	2.4 mm	Very low 1
27 Oct	-4.0 °C	59 %	26 km/h	0.0 mm	Very low 1
28 Oct	-1.6 °C	67 %	46 km/h	0.7 mm	Very low 2
29 Oct	0.2 °C	52 %	23 km/h	0.0 mm	Very low 2
30 Oct	-1.1 °C	67 %	31 km/h	1.5 mm	Very low 1
31 Oct	-0.2 °C	69 %	37 km/h	0.0 mm	Very low 2
1 Nov	1.8 °C	78 %	19 km/h	0.0 mm	Very low 2
2 Nov	0.0 °C	69 %	24 km/h	0.6 mm	Very low 2
3 Nov	-1.9 °C	78 %	18 km/h	0.2 mm	Very low 2
4 Nov	-2.1 °C	87 %	32 km/h	1.3 mm	Very low 1
5 Nov	-3.5 °C	86 %	30 km/h	0.8 mm	Very low 1
6 Nov	-0.2 °C	92 %	17 km/h	0.0 mm	Very low 0
7 Nov	-0.1 °C	95 %	45 km/h	7.5 mm	Very low 0
8 Nov	-3.3 °C	80 %	44 km/h	3.7 mm	Very low 0
9 Nov	-0.4 °C	84 %	36 km/h	0.0 mm	Very low 0
10 Nov	3.0 °C	67 %	44 km/h	0.0 mm	Very low 0
11 Nov	3.2 °C	63 %	37 km/h	0.3 mm	Very low 0
12 Nov	-3.0 °C	68 %	40 km/h	0.0 mm	Very low 0
13 Nov	-7.4 °C	88 %	22 km/h	1.2 mm	Very low 0
14 Nov	-3.7 °C	69 %	27 km/h	0.3 mm	Very low 0
15 Nov	-3.4 °C	81 %	38 km/h	3.3 mm	Very low 0
16 Nov	-2.0 °C	65 %	38 km/h	0.0 mm	Very low 0
17 Nov	2.3 °C	70 %	34 km/h	0.0 mm	Very low 0
18 Nov	2.9 °C	87 %	27 km/h	0.0 mm	Very low 0
19 Nov	2.1 °C	87 %	64 km/h	1.2 mm	Very low 0
20 Nov	-7.0 °C	47 %	62 km/h	0.4 mm	Very low 1
21 Nov	-11.1 °C	65 %	31 km/h	1.7 mm	Very low 0
22 Nov	-9.6 °C	74 %	21 km/h	0.3 mm	Very low 0
23 Nov	-3.5 °C	77 %	36 km/h	0.0 mm	Very low 0
24 Nov	0.9 °C	76 %	37 km/h	0.0 mm	Very low 0
25 Nov after	-0.7 °C	65 %	42 km/h	0.7 mm	Very low 1
26 Nov after	-2.5 °C	85 %	26 km/h	0.1 mm	Very low 0
27 Nov after	1.0 °C	67 %	46 km/h	0.1 mm	Very low 1
28 Nov after	1.1 °C	48 %	46 km/h	0.0 mm	Very low 1
29 Nov after	-1.8 °C	49 %	46 km/h	1.8 mm	Very low 0

Before and after, from space

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

↔

Before · 16 Jun 2023

After · 1 Dec 2023

Before After

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 25 September 2023 the air beside the fire reached 1,039 µg/m³ of PM2.5. That day averaged 498: 33 times the WHO daily guideline (15).

PM2.5 peak1,039 µg/m³

Days over the guideline71 days

PM101,483 µg/m³

Optical depth11.25

WHO 15

21222324252627282930123456789101112131415161718192021222324252627282930311234567891011121314151617181920212223242526272829303112345678910111213141516171819202122232425262728293012345678910111213141516171819202122232425262728293031123456789101112131415161718192021222324252627

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 · 4,454Every 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 time	Satellite	FRP (MW)	Lat	Lon

Other fires nearby

1,704 haMackenzie County16 July 2024 · 23 days · 31 km away

All fires in Canada ›

Frequently asked questions

How long did the Mackenzie County fire last?: It burned between 23 June 2023 and 24 November 2023: 155 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 29,574 hectares (295.7 km²). Other tallies, such as those of provincial agencies, may give slightly different figures.
Which census subdivisions burned?: The fire only entered Mackenzie County (28,775 ha, 0.4 %).
What was the weather like?: During the fire the temperature reached 27.6 °C, humidity dropped to 22 % and gusts hit 64 km/h. The fire danger index (FWI) reached 20, class Moderate.
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

NASA FIRMS ↗
CWFIS · Interactive map ↗

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.

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What really happened?

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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. 4,454 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.

Where it burned