How long did the Lac-Walker fire last?

It burned between 19 June 2024 and 14 July 2024: 26 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 9,885 hectares (98.8 km²). Other tallies, such as those of provincial agencies, may give slightly different figures.

Which census subdivisions burned?

The fire entered 2 census subdivisions: Lac-Walker (5,994 ha, 0.3 %); Rivière-Nipissis (3,856 ha, 0.4 %).

What was the weather like?

During the fire the temperature reached 33.4 °C, humidity dropped to 26 % and gusts hit 66 km/h. The fire danger index (FWI) reached 21, 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 · 2024-06-19 → 2024-07-14

Lac-Walker fire, 19 June 2024 Lac-Walker, Rivière-Nipissis

Out · last detection 9 Jul 2024, 06:29 UTC

The fire started on 19 June 2024 in Lac-Walker, Canada, and satellites saw it burning for 26 days. Canada’s CWFIS (Natural Resources Canada) mapped an official burnt perimeter of 9,885 hectares from satellite imagery, spread across 2 census subdivisions.

It is the 70th largest in Quebec since 2016 (of 254 with a page). Number 91 in Canada in 2024, of 291.

Compare with…

Suggestions: Rivière-Nipissis · 2023

Burnt area: 9,885ha; official perimeter (CWFIS)
Duration: 26days; 19 Jun 2024 – 14 Jul 2024
Census subdivisions hit: 2; municipalities
Started on: 19 Jun; 2024
Heat detections: 648; in a single hotspot: 203 MW
Danger at start: 4; Very low · FWI index
Average daily power: 499MW; detected power per day, on average

HOTSPOTS BY DAY 19 Jun14 Jul

Play back 9 Jul 2024

How it evolved, day by day

20 Jun 22 Jun 24 Jun 26 Jun 7 Jul 9 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

33°high

66km/h · peak gust

26%lowest humidity

It had gone one day without rain (1 mm or more) when it started. Rain came after the fire: 6.1 mm on 15 Jul.

This area had burned before

6% of the perimeter overlaps earlier fires recorded since 2016: 544 ha in 2023.

544 ha Rivière-Nipissis fire, May 2023 35,111 ha in total; the hectares shown are those it shares with this fire

How big is it?

It burned the equivalent of 6.2% of the area of London (99 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

Lac-Walker where it started

5,994 ha reached on 20 Jun

0.3 %
Rivière-Nipissis

3,856 ha reached on 26 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)
19 Jun	33.4 °C	41 %	52 km/h	6.4 mm	Very low 4
20 Jun	26.4 °C	32 %	62 km/h	0.1 mm	Moderate 13
21 Jun	22.0 °C	28 %	66 km/h	0.0 mm	Moderate 19
22 Jun	23.8 °C	29 %	45 km/h	0.0 mm	Moderate 16
23 Jun	26.6 °C	26 %	32 km/h	0.2 mm	Moderate 16
24 Jun	27.0 °C	27 %	47 km/h	0.0 mm	Moderate 20
25 Jun	25.5 °C	33 %	45 km/h	0.0 mm	Moderate 21
26 Jun	19.9 °C	72 %	45 km/h	26.0 mm	Very low 0
27 Jun	16.8 °C	46 %	32 km/h	0.2 mm	Very low 1
28 Jun	19.7 °C	34 %	43 km/h	0.1 mm	Very low 4
29 Jun	17.0 °C	68 %	44 km/h	14.8 mm	Very low 0
30 Jun	16.7 °C	87 %	34 km/h	12.0 mm	Very low 0
1 Jul	24.7 °C	28 %	46 km/h	0.0 mm	Very low 1
2 Jul	27.6 °C	33 %	34 km/h	0.4 mm	Very low 5
3 Jul	25.7 °C	41 %	48 km/h	1.1 mm	Low 6
4 Jul	22.8 °C	71 %	49 km/h	9.9 mm	Very low 0
5 Jul	21.9 °C	44 %	36 km/h	0.0 mm	Very low 1
6 Jul	23.6 °C	35 %	32 km/h	0.0 mm	Very low 5
7 Jul	28.6 °C	30 %	31 km/h	0.0 mm	Low 10
8 Jul	30.3 °C	32 %	41 km/h	0.0 mm	Moderate 14
9 Jul	26.0 °C	56 %	45 km/h	20.7 mm	Very low 0
10 Jul	28.1 °C	32 %	33 km/h	0.3 mm	Very low 4
11 Jul	25.4 °C	28 %	35 km/h	0.0 mm	Low 10
12 Jul	29.2 °C	32 %	41 km/h	0.0 mm	Moderate 14
13 Jul	29.7 °C	36 %	45 km/h	0.0 mm	Moderate 15
14 Jul	28.3 °C	47 %	36 km/h	4.2 mm	Very low 2
15 Jul after	19.8 °C	79 %	38 km/h	6.1 mm	Very low 0

Before and after, from space

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

↔

Before · 12 Jun 2024

After · 21 Jul 2024

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 26 June 2024 the air beside the fire reached 109 µg/m³ of PM2.5. That day averaged 52: 3.5 times the WHO daily guideline (15).

PM2.5 peak109 µg/m³

Days over the guideline7 days

PM10156 µg/m³

Optical depth1.29

WHO 15

17181920212223242526272829301234567891011121314151617

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 · 648Every 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

35,111 haRivière-NipissisMay 2023 · 38 days · 18 km away

All fires in Canada ›

Frequently asked questions

How long did the Lac-Walker fire last?: It burned between 19 June 2024 and 14 July 2024: 26 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 9,885 hectares (98.8 km²). Other tallies, such as those of provincial agencies, may give slightly different figures.
Which census subdivisions burned?: The fire entered 2 census subdivisions: Lac-Walker (5,994 ha, 0.3 %); Rivière-Nipissis (3,856 ha, 0.4 %).
What was the weather like?: During the fire the temperature reached 33.4 °C, humidity dropped to 26 % and gusts hit 66 km/h. The fire danger index (FWI) reached 21, 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.

Report an error

What do you think is wrong?

Dates or duration Place or towns Burned area Name It was not a wildfire Same fire as another page Something else

What really happened?

Your connection to the fire (optional) Email (optional)

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. 648 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