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Kootenay 1 fire, July 2023 Kootenay 1, East Kootenay C, East Kootenay E

Out · last detection 27 Jul 2023, 21:47 UTC

The fire started on 17 July 2023 in Kootenay 1, Canada, and satellites saw it burning for 11 days. Canada’s CWFIS (Natural Resources Canada) mapped an official burnt perimeter of 4,897 hectares from satellite imagery, spread across 4 census subdivisions.

It is the 180th largest in British Columbia since 2016 (of 449 with a page). Number 270 in Canada in 2023, of 489.

Compare with…

Suggestions: East Kootenay E · 2026East Kootenay E · 2021East Kootenay C · 2023East Kootenay E · 2026

Burnt area
4,897ha
official perimeter (CWFIS)
Duration
11days
17 Jul 2023 – 27 Jul 2023
Census subdivisions hit
4
municipalities
Started on
17 Jul
2023
Heat detections
668
in a single hotspot: 245 MW
Danger at start
21
Moderate · FWI index
Average daily power
683MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 17 Jul27 Jul
27 Jul 2023

How it evolved, day by day

17 Jul 2023 · 36 MW · 6 18 Jul 2023 · 300 MW · 72 19 Jul 2023 · 879 MW · 81 20 Jul 2023 · 3,675 MW · 223 21 Jul 2023 · 991 MW · 137 22 Jul 2023 · 810 MW · 114 23 Jul 2023 · 53 MW · 23 24 Jul 2023 · 22 MW · 4 25 Jul 2023 · 2 MW · 2 27 Jul 2023 · 65 MW · 6
17 Jul 19 Jul 20 Jul 21 Jul 23 Jul 25 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

34°high
65km/h · peak gust
16%lowest humidity

It had gone 5 days without rain (1 mm or more) when it started. Rain came after the fire: 2.2 mm on 30 Jul.

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 3.1% of the area of London (49 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

  1. Kootenay 1 where it started
    4,426 ha reached on 17 Jul
    58 %
  2. East Kootenay C
    217 ha reached on 21 Jul
    0.0 %
  3. East Kootenay E
    201 ha reached on 22 Jul
    0.0 %
  4. Cranbrook
    71 ha reached on 21 Jul
    2.2 %

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 area0.39 ha
Residents≈ 100

Inside the perimeter there were about 0.39 hectares of built-up land and about 100 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)
17 Jul 27.4 °C 26 % 65 km/h 1.8 mm Moderate 21
18 Jul 27.4 °C 23 % 38 km/h 0.0 mm High 26
19 Jul 30.5 °C 21 % 20 km/h 0.0 mm High 27
20 Jul 33.3 °C 18 % 20 km/h 0.0 mm High 32
21 Jul 34.2 °C 17 % 36 km/h 0.2 mm High 33
22 Jul 33.9 °C 16 % 43 km/h 0.0 mm Very high 39
23 Jul 34.3 °C 16 % 38 km/h 0.0 mm High 38
24 Jul 34.4 °C 18 % 60 km/h 0.4 mm Very high 45
25 Jul 26.2 °C 23 % 60 km/h 0.0 mm Very high 43
26 Jul 26.4 °C 21 % 40 km/h 0.1 mm High 36
27 Jul 27.0 °C 24 % 19 km/h 0.3 mm High 32
28 Jul after 25.1 °C 42 % 29 km/h 0.1 mm High 26
29 Jul after 31.0 °C 26 % 30 km/h 0.1 mm High 28
30 Jul after 32.7 °C 20 % 48 km/h 2.2 mm High 24

Before and after, from space

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

Before · 10 Jul 2023
After · 3 Aug 2023

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 15 July 2023 the air beside the fire reached 98 µg/m³ of PM2.5. That day averaged 41: 2.8 times the WHO daily guideline (15).

PM2.5 peak98 µg/m³
Days over the guideline4 days
PM10141 µg/m³
Optical depth2.55
15161718192021222324252627282930
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 · 668Every 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 Kootenay 1 fire last?
It burned between 17 July 2023 and 27 July 2023: 11 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 4,897 hectares (49.0 km²). Other tallies, such as those of provincial agencies, may give slightly different figures.
Which census subdivisions burned?
The fire entered 4 census subdivisions: Kootenay 1 (4,426 ha, 58 %); East Kootenay C (217 ha, 0.0 %); East Kootenay E (201 ha, 0.0 %); Cranbrook (71 ha, 2.2 %).
What was the weather like?
During the fire the temperature reached 34.4 °C, humidity dropped to 16 % and gusts hit 65 km/h. The fire danger index (FWI) reached 45, class Very 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

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
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How we know this
  • Perimeter: NBAC (Natural Resources Canada), official.
  • Dates from the perimeter: the VIIRS detections inside it did not change them. 668 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.