How long did the Big Lakes County fire last?

According to the heat detections seen by satellite inside the perimeter, it burned from 2 May 2023 to 9 September 2023 (131 days). The perimeter dates it from 4 May 2023 to 9 September 2023.

How much area did it burn?

The official perimeter mapped by Canada’s CWFIS (Natural Resources Canada) is 127,189 hectares (1,271.9 km²). Other tallies, such as those of provincial agencies, may give slightly different figures.

Which census subdivisions burned?

The fire entered 2 census subdivisions: Big Lakes County (122,293 ha, 8.1 %); Greenview No. 16 (4,305 ha, 0.1 %).

What was the weather like?

During the fire the temperature reached 30.0 °C, humidity dropped to 17 % and gusts hit 66 km/h. The fire danger index (FWI) reached 29, 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.

CA · Canada · 2023-05-02 → 2023-09-09

Big Lakes County fire, 2 May 2023 Big Lakes County, Greenview No. 16

Out · last detection 15 Aug 2023, 11:01 UTC

The fire started on 2 May 2023 in Big Lakes County, Canada, and satellites saw it burning for 131 days. Canada’s CWFIS (Natural Resources Canada) mapped an official burnt perimeter of 127,189 hectares from satellite imagery, spread across 2 census subdivisions.

It is the 9th largest in Alberta since 2016 (of 243 with a page). Number 21 in Canada in 2023, of 489.

Compare with…

Burnt area: 127,189ha; official perimeter (CWFIS)
Duration: 131days; 2 May 2023 – 9 Sept 2023
Census subdivisions hit: 2; municipalities
Started on: 2 May; 2023
Heat detections: 12,327; in a single hotspot: 1,022 MW
Danger at start: 8; Low · FWI index
Average daily power: 9.8GW; detected power per day, on average

HOTSPOTS BY DAY 2 May9 Sept

Play back 15 Aug 2023

How it evolved, day by day

2 May 5 May 7 May 14 May 18 May 3 Jun 11 Jun 6 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

30°high

66km/h · peak gust

17%lowest humidity

It had gone 4 days without rain (1 mm or more) when it started. Rain came after the fire: 1.0 mm on 12 Sept.

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 80% of the area of London (1,272 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

Big Lakes County where it started

122,293 ha reached on 2 May

8.1 %
Greenview No. 16

4,305 ha reached on 17 May

0.1 %

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 area5.9 ha

Residents≈ 250

Inside the perimeter there were about 5.9 hectares of built-up land and about 250 residents (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	23.3 °C	27 %	24 km/h	1.4 mm	Low 8
3 May	27.3 °C	23 %	42 km/h	0.0 mm	Moderate 18
4 May	28.3 °C	17 %	37 km/h	0.0 mm	High 22
5 May	25.4 °C	17 %	60 km/h	0.0 mm	High 29
6 May	17.4 °C	29 %	66 km/h	0.0 mm	High 26
7 May	10.1 °C	50 %	47 km/h	6.5 mm	Very low 1
8 May	14.2 °C	52 %	24 km/h	0.1 mm	Very low 2
9 May	17.1 °C	44 %	24 km/h	2.7 mm	Very low 1
10 May	18.7 °C	38 %	27 km/h	5.4 mm	Very low 0
11 May	18.3 °C	51 %	28 km/h	2.2 mm	Very low 1
12 May	23.4 °C	27 %	30 km/h	0.0 mm	Low 7
13 May	28.0 °C	19 %	32 km/h	0.0 mm	Moderate 17
14 May	28.9 °C	17 %	32 km/h	0.0 mm	Moderate 20
15 May	28.5 °C	25 %	33 km/h	0.0 mm	High 22
16 May	18.2 °C	30 %	42 km/h	0.0 mm	Moderate 20
17 May	18.3 °C	23 %	35 km/h	0.0 mm	Moderate 18
18 May	21.4 °C	23 %	34 km/h	0.0 mm	Moderate 20
19 May	23.7 °C	31 %	42 km/h	0.0 mm	Moderate 21
20 May	19.6 °C	51 %	31 km/h	1.6 mm	Very low 5
21 May	23.3 °C	45 %	27 km/h	11.1 mm	Very low 1
22 May	14.2 °C	92 %	49 km/h	32.3 mm	Very low 0
23 May	12.4 °C	81 %	52 km/h	15.4 mm	Very low 0
24 May	13.0 °C	67 %	41 km/h	0.3 mm	Very low 0
25 May	18.2 °C	39 %	26 km/h	0.1 mm	Very low 0
26 May	24.1 °C	25 %	31 km/h	0.5 mm	Low 6
27 May	24.9 °C	25 %	37 km/h	0.7 mm	Low 10
28 May	21.2 °C	29 %	51 km/h	0.1 mm	Moderate 13
29 May	19.7 °C	22 %	42 km/h	0.4 mm	Moderate 14
30 May	18.8 °C	43 %	37 km/h	9.5 mm	Very low 0
31 May	15.4 °C	66 %	25 km/h	4.6 mm	Very low 0
1 Jun	17.1 °C	38 %	28 km/h	0.5 mm	Very low 1
2 Jun	23.5 °C	25 %	30 km/h	0.1 mm	Low 7
3 Jun	25.7 °C	35 %	49 km/h	0.2 mm	Low 11
4 Jun	27.9 °C	32 %	38 km/h	0.7 mm	Moderate 12
5 Jun	13.1 °C	53 %	33 km/h	29.0 mm	Very low 0
6 Jun	22.0 °C	28 %	43 km/h	0.0 mm	Very low 2
7 Jun	24.4 °C	22 %	38 km/h	0.0 mm	Low 9
8 Jun	26.1 °C	29 %	38 km/h	0.0 mm	Moderate 12
9 Jun	28.7 °C	35 %	48 km/h	0.0 mm	Moderate 16
10 Jun	28.5 °C	34 %	54 km/h	7.7 mm	Very low 3
11 Jun	22.3 °C	50 %	36 km/h	0.8 mm	Very low 4
12 Jun	25.1 °C	35 %	27 km/h	0.0 mm	Low 8
13 Jun	22.3 °C	53 %	33 km/h	17.2 mm	Very low 0
14 Jun	12.2 °C	85 %	53 km/h	11.9 mm	Very low 0
15 Jun	17.8 °C	44 %	45 km/h	1.2 mm	Very low 0
16 Jun	16.1 °C	66 %	49 km/h	6.6 mm	Very low 0
17 Jun	16.1 °C	36 %	46 km/h	0.0 mm	Very low 1
18 Jun	9.4 °C	69 %	50 km/h	25.8 mm	Very low 0
19 Jun	9.9 °C	93 %	62 km/h	36.5 mm	Very low 0
20 Jun	15.8 °C	42 %	46 km/h	3.1 mm	Very low 0
21 Jun	18.5 °C	37 %	38 km/h	0.8 mm	Very low 0
22 Jun	18.3 °C	47 %	39 km/h	1.6 mm	Very low 1
23 Jun	21.9 °C	44 %	23 km/h	1.0 mm	Very low 1
24 Jun	25.8 °C	34 %	26 km/h	1.4 mm	Very low 2
25 Jun	18.8 °C	78 %	28 km/h	10.7 mm	Very low 0
26 Jun	25.0 °C	42 %	37 km/h	1.3 mm	Very low 1
27 Jun	24.5 °C	51 %	29 km/h	1.3 mm	Very low 1
28 Jun	26.1 °C	45 %	19 km/h	0.6 mm	Very low 3
29 Jun	24.4 °C	42 %	37 km/h	1.1 mm	Very low 4
30 Jun	23.4 °C	36 %	33 km/h	3.0 mm	Very low 1
1 Jul	16.9 °C	60 %	34 km/h	10.3 mm	Very low 0
2 Jul	14.9 °C	68 %	56 km/h	12.8 mm	Very low 0
3 Jul	16.7 °C	61 %	38 km/h	8.1 mm	Very low 0
4 Jul	20.6 °C	45 %	23 km/h	0.7 mm	Very low 0
5 Jul	23.4 °C	41 %	32 km/h	0.0 mm	Very low 2
6 Jul	23.3 °C	47 %	31 km/h	0.6 mm	Very low 3
7 Jul	25.2 °C	31 %	20 km/h	0.0 mm	Low 7
8 Jul	26.8 °C	41 %	24 km/h	0.0 mm	Low 8
9 Jul	28.8 °C	36 %	24 km/h	0.3 mm	Low 9
10 Jul	24.4 °C	57 %	34 km/h	4.1 mm	Very low 1
11 Jul	23.2 °C	62 %	26 km/h	3.3 mm	Very low 1
12 Jul	24.6 °C	53 %	38 km/h	1.4 mm	Very low 1
13 Jul	21.6 °C	70 %	38 km/h	3.5 mm	Very low 0
14 Jul	20.1 °C	62 %	39 km/h	1.3 mm	Very low 1
15 Jul	22.5 °C	48 %	28 km/h	1.9 mm	Very low 1
16 Jul	22.8 °C	55 %	26 km/h	8.1 mm	Very low 0
17 Jul	20.4 °C	55 %	27 km/h	5.4 mm	Very low 0
18 Jul	18.3 °C	57 %	50 km/h	0.6 mm	Very low 1
19 Jul	21.9 °C	49 %	38 km/h	0.5 mm	Very low 3
20 Jul	24.2 °C	46 %	24 km/h	0.1 mm	Very low 4
21 Jul	27.4 °C	42 %	19 km/h	1.0 mm	Very low 5
22 Jul	25.7 °C	53 %	26 km/h	11.8 mm	Very low 0
23 Jul	23.3 °C	50 %	25 km/h	15.0 mm	Very low 0
24 Jul	25.2 °C	54 %	33 km/h	15.0 mm	Very low 0
25 Jul	15.3 °C	68 %	56 km/h	7.2 mm	Very low 0
26 Jul	14.3 °C	91 %	62 km/h	49.7 mm	Very low 0
27 Jul	16.3 °C	68 %	33 km/h	6.0 mm	Very low 0
28 Jul	18.5 °C	47 %	29 km/h	0.7 mm	Very low 0
29 Jul	22.3 °C	42 %	37 km/h	0.0 mm	Very low 1
30 Jul	24.9 °C	54 %	30 km/h	4.6 mm	Very low 0
31 Jul	21.4 °C	48 %	49 km/h	1.0 mm	Very low 1
1 Aug	21.4 °C	46 %	38 km/h	0.2 mm	Very low 3
2 Aug	21.2 °C	57 %	27 km/h	9.7 mm	Very low 0
3 Aug	17.8 °C	59 %	52 km/h	7.0 mm	Very low 0
4 Aug	22.5 °C	48 %	37 km/h	1.9 mm	Very low 0
5 Aug	23.8 °C	37 %	22 km/h	0.0 mm	Very low 2
6 Aug	24.8 °C	42 %	22 km/h	0.0 mm	Very low 4
7 Aug	23.1 °C	54 %	30 km/h	3.4 mm	Very low 0
8 Aug	16.7 °C	86 %	34 km/h	9.0 mm	Very low 0
9 Aug	16.2 °C	90 %	29 km/h	24.6 mm	Very low 0
10 Aug	17.3 °C	67 %	56 km/h	8.4 mm	Very low 0
11 Aug	19.6 °C	52 %	40 km/h	1.0 mm	Very low 0
12 Aug	21.2 °C	46 %	48 km/h	0.7 mm	Very low 1
13 Aug	27.2 °C	40 %	45 km/h	0.0 mm	Very low 5
14 Aug	22.4 °C	52 %	40 km/h	0.1 mm	Very low 5
15 Aug	22.9 °C	55 %	64 km/h	2.9 mm	Very low 1
16 Aug	22.9 °C	43 %	40 km/h	0.0 mm	Very low 3
17 Aug	23.7 °C	36 %	45 km/h	0.0 mm	Low 7
18 Aug	13.1 °C	73 %	35 km/h	2.8 mm	Very low 0
19 Aug	17.2 °C	48 %	28 km/h	0.3 mm	Very low 1
20 Aug	21.4 °C	35 %	28 km/h	0.0 mm	Very low 4
21 Aug	21.5 °C	40 %	45 km/h	0.0 mm	Low 8
22 Aug	17.1 °C	88 %	26 km/h	5.1 mm	Very low 0
23 Aug	14.6 °C	98 %	27 km/h	37.1 mm	Very low 0
24 Aug	16.8 °C	82 %	35 km/h	12.5 mm	Very low 0
25 Aug	22.8 °C	45 %	29 km/h	0.0 mm	Very low 0
26 Aug	24.0 °C	43 %	38 km/h	0.0 mm	Very low 1
27 Aug	25.6 °C	41 %	27 km/h	0.0 mm	Very low 3
28 Aug	26.4 °C	39 %	28 km/h	0.0 mm	Low 6
29 Aug	30.0 °C	31 %	22 km/h	0.0 mm	Low 9
30 Aug	24.1 °C	50 %	29 km/h	0.0 mm	Low 7
31 Aug	21.3 °C	51 %	44 km/h	0.0 mm	Low 8
1 Sept	24.8 °C	28 %	52 km/h	0.0 mm	Moderate 14
2 Sept	19.9 °C	35 %	54 km/h	0.0 mm	Moderate 15
3 Sept	16.7 °C	45 %	38 km/h	1.8 mm	Very low 2
4 Sept	11.7 °C	48 %	33 km/h	0.2 mm	Very low 4
5 Sept	9.1 °C	83 %	38 km/h	5.9 mm	Very low 0
6 Sept	15.3 °C	54 %	36 km/h	1.2 mm	Very low 0
7 Sept	17.6 °C	40 %	40 km/h	0.3 mm	Very low 2
8 Sept	19.0 °C	36 %	31 km/h	0.0 mm	Very low 5
9 Sept	22.3 °C	32 %	25 km/h	0.0 mm	Low 9
10 Sept after	25.4 °C	24 %	37 km/h	0.0 mm	Moderate 15
11 Sept after	25.9 °C	27 %	38 km/h	0.4 mm	Moderate 16
12 Sept after	20.7 °C	43 %	30 km/h	1.0 mm	Low 6

Before and after, from space

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

↔

Before · 25 Apr 2023

After · 16 Sept 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 20 May 2023 the air beside the fire reached 354 µg/m³ of PM2.5. That day averaged 268: 18 times the WHO daily guideline (15).

PM2.5 peak354 µg/m³

Days over the guideline69 days

PM10507 µg/m³

Optical depth4.91

WHO 15

23456789101112131415161718192021222324252627282930311234567891011121314151617181920212223242526272829301234567891011121314151617181920212223242526272829303112345678910111213141516171819202122232425262728293031123456789101112

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 · 12,327Every 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

Frequently asked questions

How long did the Big Lakes County fire last?: According to the heat detections seen by satellite inside the perimeter, it burned from 2 May 2023 to 9 September 2023 (131 days). The perimeter dates it from 4 May 2023 to 9 September 2023.
How much area did it burn?: The official perimeter mapped by Canada’s CWFIS (Natural Resources Canada) is 127,189 hectares (1,271.9 km²). Other tallies, such as those of provincial agencies, may give slightly different figures.
Which census subdivisions burned?: The fire entered 2 census subdivisions: Big Lakes County (122,293 ha, 8.1 %); Greenview No. 16 (4,305 ha, 0.1 %).
What was the weather like?: During the fire the temperature reached 30.0 °C, humidity dropped to 17 % and gusts hit 66 km/h. The fire danger index (FWI) reached 29, 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

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

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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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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; 2 polygons grouped in this page.
Dates adjusted with the VIIRS detections inside the perimeter, which said 4 May 2023 to 9 September 2023. 12,327 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