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Kenora, Unorganized fire, 29 July 2017 Kenora, Unorganized

Out · last detection 1 Sept 2017, 18:30 UTC

The fire started on 29 July 2017 in Kenora, Unorganized, Canada, and satellites saw it burning for 35 days. Canada’s CWFIS (Natural Resources Canada) mapped an official burnt perimeter of 7,246 hectares from satellite imagery, spread across a single census subdivision.

It is the 47th largest in Ontario since 2016 (of 144 with a page). Number 63 in Canada in 2017, of 242.

Burnt area
7,246ha
official perimeter (CWFIS)
Duration
35days
29 Jul 2017 – 1 Sept 2017
Census subdivisions hit
1
municipalities
Started on
29 Jul
2017
Heat detections
1,284
in a single hotspot: 199 MW
Danger at start
14
Moderate · FWI index
Average daily power
668MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 29 Jul1 Sept
1 Sept 2017

How it evolved, day by day

10 Aug 2017 · 257 MW · 4 11 Aug 2017 · 197 MW · 27 12 Aug 2017 · 2,464 MW · 324 13 Aug 2017 · 2,625 MW · 312 16 Aug 2017 · 37 MW · 3 19 Aug 2017 · 1,477 MW · 51 20 Aug 2017 · 356 MW · 128 21 Aug 2017 · 11 MW · 13 25 Aug 2017 · 32 MW · 5 26 Aug 2017 · 921 MW · 40 27 Aug 2017 · 1,190 MW · 270 28 Aug 2017 · 373 MW · 38 29 Aug 2017 · 79 MW · 66 30 Aug 2017 · 1 MW · 1 1 Sept 2017 · 6 MW · 2
10 Aug 13 Aug 20 Aug 26 Aug 29 Aug

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
55km/h · peak gust
35%lowest humidity

It had gone 2 days without rain (1 mm or more) when it started. Rain came after the fire: 12.2 mm on 2 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 4.6% of the area of London (72 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. Kenora, Unorganized where it started
    7,182 ha reached on 10 Aug
    0.0 %

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 2015
Built-up area< 0.1 ha
Residents< 20

Inside the perimeter there was no noticeable built-up land and almost nobody lived there (GHSL 2015, 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)
29 Jul 28.7 °C 42 % 42 km/h 0.0 mm Moderate 14
30 Jul 23.6 °C 53 % 33 km/h 0.0 mm Moderate 12
31 Jul 23.8 °C 57 % 52 km/h 12.6 mm Very low 1
1 Aug 18.0 °C 67 % 53 km/h 0.0 mm Very low 3
2 Aug 15.0 °C 47 % 39 km/h 0.3 mm Very low 4
3 Aug 18.7 °C 50 % 40 km/h 0.0 mm Low 7
4 Aug 18.9 °C 42 % 31 km/h 0.0 mm Low 8
5 Aug 14.5 °C 62 % 32 km/h 0.0 mm Low 7
6 Aug 19.2 °C 42 % 21 km/h 0.0 mm Low 7
7 Aug 23.3 °C 50 % 38 km/h 4.1 mm Very low 2
8 Aug 18.1 °C 49 % 38 km/h 0.3 mm Very low 4
9 Aug 19.4 °C 42 % 42 km/h 0.0 mm Low 8
10 Aug 19.5 °C 41 % 22 km/h 0.0 mm Low 8
11 Aug 23.0 °C 40 % 21 km/h 0.2 mm Low 10
12 Aug 23.0 °C 37 % 26 km/h 0.0 mm Moderate 11
13 Aug 19.6 °C 52 % 19 km/h 0.6 mm Low 8
14 Aug 18.5 °C 56 % 34 km/h 6.5 mm Very low 1
15 Aug 20.2 °C 45 % 28 km/h 0.0 mm Very low 2
16 Aug 22.5 °C 48 % 23 km/h 0.0 mm Low 6
17 Aug 21.8 °C 49 % 24 km/h 0.4 mm Low 7
18 Aug 21.6 °C 60 % 17 km/h 1.4 mm Very low 2
19 Aug 23.8 °C 44 % 36 km/h 0.0 mm Low 9
20 Aug 21.7 °C 54 % 41 km/h 6.9 mm Very low 1
21 Aug 21.6 °C 38 % 51 km/h 0.0 mm Low 6
22 Aug 16.1 °C 74 % 55 km/h 4.5 mm Very low 0
23 Aug 15.0 °C 35 % 46 km/h 0.0 mm Very low 3
24 Aug 16.9 °C 45 % 30 km/h 0.0 mm Very low 4
25 Aug 20.5 °C 40 % 26 km/h 0.0 mm Low 8
26 Aug 22.2 °C 38 % 35 km/h 0.0 mm Low 10
27 Aug 21.4 °C 44 % 27 km/h 0.0 mm Low 10
28 Aug 22.6 °C 53 % 38 km/h 0.0 mm Moderate 12
29 Aug 20.4 °C 65 % 44 km/h 4.6 mm Very low 1
30 Aug 13.8 °C 59 % 39 km/h 0.3 mm Very low 2
31 Aug 16.7 °C 42 % 26 km/h 0.0 mm Very low 4
1 Sept 19.9 °C 44 % 50 km/h 0.0 mm Low 10
2 Sept after 19.4 °C 61 % 41 km/h 12.2 mm Very low 0

Its twins: fires that started in the same weather

It started with an FWI of 13.5, a minimum humidity of 42% and 2 days without rain. Fires in the area that started in weather like this since 2018: 16.

FWI at the start 13.5
Minimum humidity 42 %
Days without rain 2
this fire chosen twins rest of the area
Almost identicalSimilar

Outlines of the closest twins

Kenora, Unorganized fire, June 2023
5,716 ha 17 days FWI 12.4 Min. humidity 42 % 155 km away, in 2023

First rain (1 mm or more) after it ended: 13.2 mm on 7 Jul.

What happened to them

21 days
median duration
5,426 ha
median area
25 %
went past 10,000 ha
9.2 mm
rain at the end (median; 16 of 16 had it)

It burned an area similar to its twins (7,246 ha against a median of 5,426 ha) and lasted 35 days, against 21 days.

All of them had rain in the ten days after the end: the first rainy day brought a median of 9.2 mm.

This is a bank of analogues: it shows what usually happens, not what will happen. With fewer than 15 twins we give no figures. How we calculate it

How it ended

12.2 mmfirst rain
2 Septthe day after it ended
55km/h · max. gust

It was considered over on 1 Sept, and on 2 Sept 12.2 mm fell. We do not know whether the rain or the firefighters put it out. Twins with rain when they ended: 16 of 16, with a median of 9.2 mm.

Weather on this page: Open-Meteo.com (CC BY 4.0) · Copernicus Climate Change Service (ERA5)

How a twin is chosen

  • Same area: fires that have already ended, less than 250 km from this one, since 2018.
  • Same start: we compare the FWI on the first day, the minimum humidity that day and the run of days without rain before it. The slider sets how much they may differ.
  • Only pages with final weather data (ERA5 reanalysis) calculated in the same way as this fire’s; agricultural and grass burns and pages with data under review are left out.
  • Fires burning at the same time as this one (a week before or after) are left out: they share the same spell of weather and do not count as a precedent.
  • They are sorted by similarity, and the outlines of the first five are drawn.

How we calculate it

Before and after, from space

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

Before · 22 Jul 2017
After · 8 Sept 2017

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 · 1,284Every 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 Kenora, Unorganized fire last?
It burned between 29 July 2017 and 1 September 2017: 35 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 7,246 hectares (72.5 km²). Other tallies, such as those of provincial agencies, may give slightly different figures.
Which census subdivisions burned?
The fire only entered Kenora, Unorganized (7,182 ha, 0.0 %).
What was the weather like?
During the fire the temperature reached 28.7 °C, humidity dropped to 35 % and gusts hit 55 km/h. The fire danger index (FWI) reached 14, 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.
How did the fires that started in similar weather in this area end?
Fires less than 250 km away that started since 2018 with a similar FWI, humidity and dry spell: 16. Their median duration was 21 days and their median area 5,426 ha; 25 % went past 10,000 ha. All of them had rain in the ten days after the end: the first rainy day brought a median of 9.2 mm.

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
What do you think is wrong?

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. 1,284 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 2015, 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.