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CA · Canada · –

Cariboo I fire, 28 August 2025 Cariboo I, Bulkley-Nechako E, Cariboo J

Out · last detection 17 Sept 2025, 10:39 UTC

The fire started on 28 August 2025 in Cariboo I, Canada, and satellites saw it burning for 21 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 14,964 hectares from heat detections, spread across 4 municipalities.

Number 69 in Canada in 2025, of 667.

GWIS near-real-time perimeter (Canada, 2025-2026, until NBAC publishes its own): this fire is not compared with fires from earlier years.

Burnt area
14,964ha
GWIS perimeter (Copernicus)
Duration
21days
28 Aug 2025 – 17 Sept 2025
Municipalities hit
4
municipalities
Started on
28 Aug
2025
Heat detections
3,243
in a single hotspot: 339 MW
Danger at start
20
Moderate · FWI index
Average daily power
3.6GW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 28 Aug17 Sept
17 Sept 2025

How it evolved, day by day

28 Aug 2025 · 4,668 MW · 130 29 Aug 2025 · 4,091 MW · 259 30 Aug 2025 · 5,836 MW · 317 31 Aug 2025 · 2,423 MW · 146 1 Sept 2025 · 5,404 MW · 186 2 Sept 2025 · 2,658 MW · 274 3 Sept 2025 · 1,462 MW · 149 4 Sept 2025 · 3,783 MW · 188 5 Sept 2025 · 4,604 MW · 336 6 Sept 2025 · 1,952 MW · 177 7 Sept 2025 · 15,040 MW · 383 8 Sept 2025 · 5,403 MW · 342 9 Sept 2025 · 2,365 MW · 135 10 Sept 2025 · 719 MW · 92 11 Sept 2025 · 533 MW · 94 16 Sept 2025 · 162 MW · 19 17 Sept 2025 · 24 MW · 16
28 Aug 1 Sept 7 Sept 17 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

29°high
36km/h · peak gust
18%lowest humidity

It had gone 8 days without rain (1 mm or more) when it started. Rain came after the fire: 3.2 mm on 20 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 9.5% of the area of London (150 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 town

  1. Cariboo I where it started
    9,091 ha reached on 28 Aug
    0.8 %
  2. 4,601 ha reached on 28 Aug
    0.3 %
  3. 1,145 ha reached on 29 Aug
    0.0 %
  4. 72 ha reached on 29 Aug
    98 %

Burnt area inside each municipality, from crossing the GWIS 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)
28 Aug 28.8 °C 23 % 25 km/h 0.0 mm Moderate 20
29 Aug 28.0 °C 18 % 21 km/h 0.0 mm Moderate 20
30 Aug 25.6 °C 28 % 26 km/h 0.0 mm Moderate 21
31 Aug 26.1 °C 32 % 19 km/h 0.0 mm Moderate 18
1 Sept 28.5 °C 25 % 27 km/h 0.4 mm High 23
2 Sept 26.5 °C 33 % 24 km/h 0.0 mm High 22
3 Sept 27.2 °C 26 % 24 km/h 0.0 mm High 23
4 Sept 26.3 °C 32 % 24 km/h 0.0 mm High 22
5 Sept 24.7 °C 33 % 17 km/h 0.0 mm Moderate 21
6 Sept 22.4 °C 41 % 23 km/h 0.0 mm Moderate 19
7 Sept 22.9 °C 33 % 29 km/h 0.0 mm High 23
8 Sept 20.7 °C 37 % 27 km/h 0.0 mm Moderate 21
9 Sept 21.0 °C 33 % 25 km/h 0.0 mm High 22
10 Sept 22.6 °C 34 % 20 km/h 0.0 mm Moderate 18
11 Sept 21.2 °C 40 % 31 km/h 0.0 mm High 22
12 Sept 17.3 °C 64 % 13 km/h 0.6 mm Moderate 13
13 Sept 20.2 °C 51 % 29 km/h 2.9 mm Very low 5
14 Sept 13.8 °C 55 % 33 km/h 16.4 mm Very low 0
15 Sept 19.6 °C 32 % 18 km/h 0.0 mm Very low 1
16 Sept 24.0 °C 25 % 35 km/h 0.0 mm Low 8
17 Sept 14.4 °C 68 % 36 km/h 4.8 mm Low 6
18 Sept after 16.1 °C 38 % 20 km/h 0.0 mm Very low 1
19 Sept after 17.6 °C 46 % 23 km/h 0.5 mm Very low 3
20 Sept after 15.2 °C 54 % 49 km/h 3.2 mm Very low 5

Before and after, from space

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

Before · 21 Aug 2025
After · 24 Sept 2025

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 7 September 2025 the air beside the fire reached 797 µg/m³ of PM2.5. That day averaged 451: 30 times the WHO daily guideline (15).

PM2.5 peak797 µg/m³
Days over the guideline22 days
PM10816 µg/m³
Optical depth3.55
26 Aug1 Sept7 Sept13 Sept19 Sept
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 · 3,243Every 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 Cariboo I fire last?
GWIS (Copernicus) dates it between 28 August 2025 and 17 September 2025: 21 days between the first and last heat detection of the perimeter.
How much area did it burn?
The perimeter GWIS (Copernicus) rebuilt from heat detections is 14,964 hectares (149.6 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire entered 4 municipalities: Cariboo I (9,091 ha, 0.8 %); Bulkley-Nechako E (4,601 ha, 0.3 %); Cariboo J (1,145 ha, 0.0 %); Tzetzi Lake 11 (72 ha, 98 %).
What was the weather like?
During the fire the temperature reached 28.8 °C, humidity dropped to 18 % and gusts hit 36 km/h. The fire danger index (FWI) reached 23, class High.
Where does this data come from?
From the GWIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of Canada (geoBoundaries). 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.

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
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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: GWIS (Copernicus), rebuilt from heat detections rather than mapped on imagery.
  • Dates from the perimeter: the VIIRS detections inside it did not change them. 3,243 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 comes from the Copernicus Global Wildfire Information System (GWIS), which rebuilds it from MODIS and VIIRS heat detections and publishes it under CC BY 4.0. It is not measured on imagery as in Europe, so it is an estimate. Heat detections come from the VIIRS sensors aboard Suomi-NPP and NOAA-20, distributed by NASA FIRMS at 375 m resolution. Municipal boundaries come from geoBoundaries ADM3 (Open Data Commons Open Database License 1.0). The area per municipality is computed by WorldFires by crossing the perimeter with those boundaries, so it may differ from each country’s official figure.