Skip to content
worldfires
en
CA · Canada · →

Yellowhead County fire, 5 May 2023 Yellowhead County, Woodlands County

Out · last detection 10 Jun 2023, 19:48 UTC

The fire started on 5 May 2023 in Yellowhead County, Canada, and satellites saw it burning for 37 days. Canada’s CWFIS (Natural Resources Canada) mapped an official burnt perimeter of 15,170 hectares from satellite imagery, spread across 2 census subdivisions.

It is the 49th largest in Alberta since 2016 (of 243 with a page). Number 121 in Canada in 2023, of 489.

Compare with…
Burnt area
15,170ha
official perimeter (CWFIS)
Duration
37days
5 May 2023 – 10 Jun 2023
Census subdivisions hit
2
municipalities
Started on
5 May
2023
Heat detections
1,863
in a single hotspot: 861 MW
Danger at start
31
High · FWI index
Average daily power
3.5GW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 5 May10 Jun
10 Jun 2023

How it evolved, day by day

5 May 2023 · 8,015 MW · 57 6 May 2023 · 1,138 MW · 240 14 May 2023 · 85 MW · 12 15 May 2023 · 178 MW · 42 16 May 2023 · 2,199 MW · 66 17 May 2023 · 1,664 MW · 80 18 May 2023 · 3,919 MW · 237 19 May 2023 · 32,075 MW · 346 20 May 2023 · 1,704 MW · 483 21 May 2023 · 279 MW · 48 27 May 2023 · 22 MW · 2 28 May 2023 · 25 MW · 3 7 Jun 2023 · 412 MW · 10 8 Jun 2023 · 1,191 MW · 50 9 Jun 2023 · 3,355 MW · 118 10 Jun 2023 · 78 MW · 69
5 May 15 May 18 May 19 May 21 May 7 Jun 10 Jun

Fire radiative power detected each day, in megawatts, and number of hotspots. The magenta bar marks the peak day.

The weather it burned in

30°high
63km/h · peak gust
15%lowest humidity

It had gone 8 days without rain (1 mm or more) when it started. Rain came after the fire: 5.1 mm on 13 Jun.

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 9.6% of the area of London (152 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. Yellowhead County where it started
    15,105 ha reached on 5 May
    0.7 %
  2. Woodlands County
    219 ha reached on 5 May
    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 2025
Built-up area0.93 ha
Residents≈ 100

Inside the perimeter there were about 0.93 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)
5 May 24.5 °C 18 % 58 km/h 0.0 mm High 31
6 May 16.9 °C 28 % 63 km/h 0.3 mm High 26
7 May 13.1 °C 47 % 40 km/h 10.0 mm Very low 0
8 May 14.2 °C 55 % 23 km/h 2.4 mm Very low 0
9 May 15.6 °C 52 % 26 km/h 3.5 mm Very low 0
10 May 16.9 °C 49 % 29 km/h 1.7 mm Very low 1
11 May 17.4 °C 53 % 28 km/h 1.0 mm Very low 1
12 May 23.3 °C 27 % 20 km/h 0.0 mm Low 8
13 May 27.4 °C 18 % 27 km/h 0.0 mm Moderate 17
14 May 27.5 °C 16 % 31 km/h 0.0 mm Moderate 20
15 May 28.3 °C 26 % 24 km/h 0.0 mm Moderate 20
16 May 20.5 °C 24 % 36 km/h 0.0 mm High 21
17 May 20.8 °C 24 % 26 km/h 0.0 mm Moderate 20
18 May 19.6 °C 29 % 38 km/h 0.0 mm Moderate 20
19 May 25.8 °C 23 % 47 km/h 0.1 mm High 23
20 May 23.6 °C 36 % 30 km/h 4.9 mm Very low 3
21 May 25.1 °C 34 % 31 km/h 10.2 mm Very low 1
22 May 14.3 °C 83 % 35 km/h 31.0 mm Very low 0
23 May 12.1 °C 76 % 47 km/h 20.7 mm Very low 0
24 May 16.0 °C 45 % 38 km/h 0.2 mm Very low 0
25 May 18.5 °C 42 % 23 km/h 0.0 mm Very low 1
26 May 22.2 °C 32 % 32 km/h 0.0 mm Very low 5
27 May 24.3 °C 29 % 24 km/h 0.0 mm Low 9
28 May 23.1 °C 33 % 38 km/h 1.8 mm Very low 3
29 May 21.4 °C 34 % 30 km/h 1.7 mm Very low 2
30 May 20.3 °C 53 % 34 km/h 4.0 mm Very low 1
31 May 15.6 °C 66 % 29 km/h 10.4 mm Very low 0
1 Jun 15.7 °C 49 % 24 km/h 2.3 mm Very low 0
2 Jun 22.1 °C 33 % 34 km/h 0.0 mm Very low 2
3 Jun 24.1 °C 40 % 40 km/h 0.1 mm Low 6
4 Jun 26.9 °C 38 % 36 km/h 6.1 mm Very low 2
5 Jun 15.1 °C 53 % 45 km/h 1.3 mm Very low 2
6 Jun 22.2 °C 26 % 28 km/h 0.0 mm Low 7
7 Jun 27.3 °C 15 % 21 km/h 0.0 mm Moderate 16
8 Jun 27.2 °C 29 % 42 km/h 0.0 mm Moderate 18
9 Jun 29.5 °C 25 % 53 km/h 0.0 mm High 22
10 Jun 28.3 °C 36 % 52 km/h 1.9 mm Low 10
11 Jun after 23.7 °C 41 % 33 km/h 0.1 mm Low 10
12 Jun after 27.5 °C 26 % 19 km/h 0.0 mm Moderate 16
13 Jun after 26.5 °C 36 % 41 km/h 5.1 mm Very low 4

Before and after, from space

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

Before · 28 Apr 2023
After · 17 Jun 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 12 June 2023 the air beside the fire reached 631 µg/m³ of PM2.5. That day averaged 339: 23 times the WHO daily guideline (15).

PM2.5 peak631 µg/m³
Days over the guideline24 days
PM10902 µg/m³
Optical depth3.04
34567891011121314151617181920212223242526272829303112345678910111213
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 · 1,863Every 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

Frequently asked questions

How long did the Yellowhead County fire last?
It burned between 5 May 2023 and 10 June 2023: 37 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 15,170 hectares (151.7 km²). Other tallies, such as those of provincial agencies, may give slightly different figures.
Which census subdivisions burned?
The fire entered 2 census subdivisions: Yellowhead County (15,105 ha, 0.7 %); Woodlands County (219 ha, 0.0 %).
What was the weather like?
During the fire the temperature reached 29.5 °C, humidity dropped to 15 % and gusts hit 63 km/h. The fire danger index (FWI) reached 31, 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 ›

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
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. 1,863 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.