Mossey River fire, April 2021 Mossey River, Lakeshore
The fire started on 4 April 2021 in Mossey River, Canada, and satellites saw it burning for 46 days. Canada’s CWFIS (Natural Resources Canada) mapped an official burnt perimeter of 3,576 hectares from satellite imagery, spread across 2 census subdivisions.
It is the 228th largest in Manitoba since 2016 (of 509 with a page). Number 171 in Canada in 2021, of 304.
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Suggestions: Mountain (South) · 2021
- Burnt area
- 3,576ha
- official perimeter (CWFIS)
- Duration
- 46days
- 4 Apr 2021 – 19 May 2021
- Census subdivisions hit
- 2
- municipalities
- Started on
- 4 Apr
- 2021
- Heat detections
- 249
- in a single hotspot: 402 MW
- Danger at start
- 2
- Very low · FWI index
- Average daily power
- 1.3GW
- detected power per day, on average
Where it burned
How it evolved, day by day
Fire radiative power detected each day, in megawatts, and number of hotspots. The magenta bar marks the peak day.
The weather it burned in
It had gone 4 days without rain (1 mm or more) when it started. Rain came after the fire: 5.4 mm on 21 May.
This area had burned before
No earlier perimeters overlap this fire since 2016, when the satellite record begins.
How big is it?
London boundary: geoBoundaries · Office for National Statistics (Open Government Licence v3.0).
Paris boundary: geoBoundaries · Institut national de l'information géographique et forestière (IGN-F) (Etalab Open License 2.0).
Madrid boundary: geoBoundaries · Open Data ESRI, IGN Central Registry of Cartography Area (CC BY 4.0).
Berlin boundary: geoBoundaries · Federal Agency for Cartography and Geodesy (dl-de/by-2-0).
This compares size, not location: both shapes are at the same scale, north up, centred on each other.
What happened to each census subdivision
-
Mossey River where it started3,545 ha reached on 16 May3.1 %
-
4 ha reached on 16 May0.0 %
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 2020Inside the perimeter there was no noticeable built-up land and almost nobody lived there (GHSL 2020, 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.
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) |
|---|---|---|---|---|---|
| 4 Apr | 9.7 °C | 38 % | 33 km/h | 0.0 mm | Very low 2 |
| 5 Apr | 9.7 °C | 40 % | 44 km/h | 0.2 mm | Very low 4 |
| 6 Apr | 11.7 °C | 34 % | 26 km/h | 0.0 mm | Very low 4 |
| 7 Apr | 14.8 °C | 32 % | 29 km/h | 0.0 mm | Low 5 |
| 8 Apr | 12.8 °C | 41 % | 32 km/h | 0.0 mm | Low 6 |
| 9 Apr | 6.0 °C | 61 % | 44 km/h | 0.0 mm | Very low 5 |
| 10 Apr | 11.0 °C | 40 % | 37 km/h | 0.0 mm | Very low 5 |
| 11 Apr | 6.5 °C | 62 % | 44 km/h | 1.1 mm | Very low 2 |
| 12 Apr | -0.9 °C | 87 % | 56 km/h | 21.5 mm | Very low 0 |
| 13 Apr | -4.0 °C | 79 % | 53 km/h | 7.7 mm | Very low 0 |
| 14 Apr | -0.8 °C | 67 % | 37 km/h | 0.0 mm | Very low 0 |
| 15 Apr | 2.8 °C | 63 % | 15 km/h | 0.0 mm | Very low 0 |
| 16 Apr | 8.7 °C | 33 % | 16 km/h | 0.0 mm | Very low 0 |
| 17 Apr | 12.2 °C | 30 % | 19 km/h | 0.0 mm | Very low 1 |
| 18 Apr | 3.8 °C | 64 % | 55 km/h | 1.5 mm | Very low 1 |
| 19 Apr | 0.1 °C | 52 % | 45 km/h | 0.0 mm | Very low 1 |
| 20 Apr | 1.3 °C | 58 % | 41 km/h | 0.0 mm | Very low 1 |
| 21 Apr | 16.1 °C | 15 % | 23 km/h | 0.0 mm | Very low 4 |
| 22 Apr | 14.7 °C | 26 % | 68 km/h | 0.1 mm | Moderate 12 |
| 23 Apr | 1.8 °C | 41 % | 46 km/h | 0.3 mm | Low 7 |
| 24 Apr | 6.3 °C | 29 % | 35 km/h | 0.0 mm | Low 6 |
| 25 Apr | 8.2 °C | 33 % | 31 km/h | 0.0 mm | Low 6 |
| 26 Apr | 8.3 °C | 58 % | 26 km/h | 0.0 mm | Very low 4 |
| 27 Apr | 5.9 °C | 45 % | 35 km/h | 0.0 mm | Very low 5 |
| 28 Apr | 3.8 °C | 48 % | 30 km/h | 1.5 mm | Very low 1 |
| 29 Apr | 8.6 °C | 30 % | 38 km/h | 2.7 mm | Very low 1 |
| 30 Apr | 11.5 °C | 43 % | 45 km/h | 0.4 mm | Very low 2 |
| 1 May | 13.7 °C | 47 % | 34 km/h | 0.0 mm | Very low 3 |
| 2 May | 4.7 °C | 80 % | 33 km/h | 2.0 mm | Very low 0 |
| 3 May | 3.2 °C | 59 % | 41 km/h | 1.3 mm | Very low 1 |
| 4 May | 6.5 °C | 41 % | 27 km/h | 0.0 mm | Very low 1 |
| 5 May | 10.5 °C | 29 % | 24 km/h | 0.0 mm | Very low 2 |
| 6 May | 7.6 °C | 42 % | 50 km/h | 0.0 mm | Low 6 |
| 7 May | 9.8 °C | 37 % | 23 km/h | 0.0 mm | Very low 5 |
| 8 May | 10.4 °C | 32 % | 30 km/h | 0.0 mm | Low 7 |
| 9 May | 9.4 °C | 38 % | 28 km/h | 0.0 mm | Low 7 |
| 10 May | 11.6 °C | 34 % | 22 km/h | 0.0 mm | Low 7 |
| 11 May | 19.3 °C | 18 % | 25 km/h | 0.0 mm | Moderate 12 |
| 12 May | 19.7 °C | 19 % | 26 km/h | 0.0 mm | Moderate 15 |
| 13 May | 21.7 °C | 18 % | 28 km/h | 0.0 mm | Moderate 15 |
| 14 May | 17.7 °C | 38 % | 28 km/h | 0.6 mm | Moderate 12 |
| 15 May | 18.8 °C | 43 % | 19 km/h | 0.0 mm | Low 10 |
| 16 May | 23.4 °C | 27 % | 41 km/h | 0.0 mm | Moderate 17 |
| 17 May | 26.9 °C | 26 % | 42 km/h | 0.0 mm | High 22 |
| 18 May | 27.8 °C | 32 % | 52 km/h | 0.0 mm | High 24 |
| 19 May | 21.6 °C | 20 % | 50 km/h | 0.0 mm | High 26 |
| 20 May after | 7.2 °C | 63 % | 50 km/h | 0.0 mm | Moderate 14 |
| 21 May after | 4.6 °C | 78 % | 40 km/h | 5.4 mm | Very low 0 |
Before and after, from space
Drag the line to compare the same ground before the fire and after it.
If the day is cloudy, change the date: each satellite passes once a day. In false colour the burnt ground looks brown or red.
Detections table · 249Every satellite heat detection, one by one, with time, satellite, power and coordinates.
| Date and time | Satellite | FRP (MW) | Lat | Lon |
|---|
Other fires nearby
Frequently asked questions
- How long did the Mossey River fire last?
- According to the heat detections seen by satellite inside the perimeter, it burned from 4 April 2021 to 19 May 2021 (46 days). The perimeter dates it from 4 April 2021 to 18 May 2021.
- How much area did it burn?
- The official perimeter mapped by Canada’s CWFIS (Natural Resources Canada) is 3,576 hectares (35.8 km²). Other tallies, such as those of provincial agencies, may give slightly different figures.
- Which census subdivisions burned?
- The fire entered 2 census subdivisions: Mossey River (3,545 ha, 3.1 %); Lakeshore (4 ha, 0.0 %).
- What was the weather like?
- During the fire the temperature reached 27.8 °C, humidity dropped to 15 % and gusts hit 68 km/h. The fire danger index (FWI) reached 26, 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 ›
- CIFFC · Canadian Interagency Forest Fire Centre ↗
- CWFIS · Canadian Wildland Fire Information System ↗
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.
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
How we know this
- Perimeter: NBAC (Natural Resources Canada), official.
- Dates adjusted with the VIIRS detections inside the perimeter, which said 4 April 2021 to 18 May 2021. 249 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 2020, 100 m cells), summed inside the perimeter: an estimate of what was there, not a damage count.
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.