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West Arnhem fire, 9 August 2021 West Arnhem

Out · last detection 18 Sept 2021, 04:28 UTC

The fire started on 9 August 2021 in West Arnhem, Australia, and satellites saw it burning for 40 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 13,824 hectares from heat detections, spread across a single municipality.

It is the 1003th largest in Northern Territory since 2016 (of 3521 with a page). Number 119 in Australia in 2021, of 460.

Compare with…

Suggestions: West Arnhem · 2017West Arnhem · 2018West Arnhem · 2018West Arnhem · 2017

Burnt area
13,824ha
GWIS perimeter (Copernicus)
Duration
40days
9 Aug 2021 – 17 Sept 2021
Municipalities hit
1
local government areas
Started on
9 Aug
2021
Heat detections
585
in a single hotspot: 56 MW
Danger at start
41
Very high · FWI index
Average daily power
98MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 9 Aug17 Sept
18 Sept 2021

How it evolved, day by day

9 Aug 2021 · 45 MW · 8 10 Aug 2021 · 6 MW · 1 11 Aug 2021 · 7 MW · 2 13 Aug 2021 · 10 MW · 3 14 Aug 2021 · 14 MW · 3 15 Aug 2021 · 210 MW · 20 16 Aug 2021 · 250 MW · 38 17 Aug 2021 · 170 MW · 32 18 Aug 2021 · 234 MW · 24 19 Aug 2021 · 10 MW · 4 20 Aug 2021 · 274 MW · 28 21 Aug 2021 · 191 MW · 35 22 Aug 2021 · 171 MW · 20 23 Aug 2021 · 76 MW · 9 24 Aug 2021 · 24 MW · 5 25 Aug 2021 · 12 MW · 4 26 Aug 2021 · 129 MW · 14 27 Aug 2021 · 218 MW · 22 28 Aug 2021 · 116 MW · 22 29 Aug 2021 · 61 MW · 14 30 Aug 2021 · 211 MW · 35 31 Aug 2021 · 121 MW · 27 1 Sept 2021 · 52 MW · 11 2 Sept 2021 · 13 MW · 1 3 Sept 2021 · 48 MW · 5 4 Sept 2021 · 12 MW · 2 5 Sept 2021 · 114 MW · 19 6 Sept 2021 · 232 MW · 31 7 Sept 2021 · 163 MW · 39 8 Sept 2021 · 30 MW · 18 9 Sept 2021 · 162 MW · 12 10 Sept 2021 · 104 MW · 24 11 Sept 2021 · 36 MW · 5 12 Sept 2021 · 143 MW · 22 13 Sept 2021 · 33 MW · 3 14 Sept 2021 · 37 MW · 8 16 Sept 2021 · 10 MW · 2 17 Sept 2021 · 23 MW · 5 18 Sept 2021 · 59 MW · 8
9 Aug 16 Aug 20 Aug 22 Aug 28 Aug 3 Sept 9 Sept 16 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

37°high
59km/h · peak gust
13%lowest humidity

It had gone 46 days without rain (1 mm or more) when it started.

This area had burned before

94% of the perimeter overlaps earlier fires recorded since 2016: 2,206 ha in 2016, 6,029 ha in 2017, 7,339 ha in 2018, 9,710 ha in 2019, 376 ha in 2020. Part of it burned more than once, so the yearly figures add up to more than the 13,030 ha that had burned before.

How big is it?

10 km
It burned the equivalent of 8.7% of the area of London (138 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. West Arnhem where it started
    13,898 ha reached on 9 Aug
    0.3 %

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 2020
Built-up area< 0.1 ha
Residents< 20

Inside 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)
9 Aug 32.7 °C 30 % 38 km/h 0.0 mm Very high 41
10 Aug 33.8 °C 32 % 35 km/h 0.0 mm High 38
11 Aug 34.9 °C 30 % 32 km/h 0.0 mm Very high 39
12 Aug 35.2 °C 28 % 45 km/h 0.0 mm Very high 43
13 Aug 34.4 °C 24 % 50 km/h 0.0 mm Very high 45
14 Aug 33.1 °C 35 % 48 km/h 0.0 mm Very high 43
15 Aug 34.4 °C 32 % 58 km/h 0.0 mm Very high 46
16 Aug 34.9 °C 27 % 50 km/h 0.0 mm Very high 45
17 Aug 33.6 °C 28 % 43 km/h 0.0 mm Very high 40
18 Aug 34.2 °C 25 % 39 km/h 0.0 mm Very high 39
19 Aug 34.2 °C 26 % 34 km/h 0.0 mm High 38
20 Aug 33.9 °C 26 % 36 km/h 0.0 mm Very high 38
21 Aug 34.8 °C 15 % 45 km/h 0.0 mm Very high 50
22 Aug 36.5 °C 25 % 29 km/h 0.0 mm Very high 45
23 Aug 35.6 °C 34 % 38 km/h 0.0 mm Very high 39
24 Aug 34.3 °C 38 % 44 km/h 0.4 mm Very high 39
25 Aug 34.2 °C 24 % 41 km/h 0.0 mm Very high 40
26 Aug 34.9 °C 18 % 39 km/h 0.0 mm Very high 46
27 Aug 36.0 °C 13 % 43 km/h 0.0 mm Extreme 52
28 Aug 35.4 °C 13 % 44 km/h 0.0 mm Extreme 56
29 Aug 36.1 °C 14 % 39 km/h 0.0 mm Very high 50
30 Aug 36.8 °C 14 % 31 km/h 0.0 mm Very high 49
31 Aug 36.4 °C 26 % 38 km/h 0.0 mm Very high 48
1 Sept 36.1 °C 33 % 41 km/h 0.0 mm Very high 43
2 Sept 34.9 °C 42 % 46 km/h 0.0 mm High 38
3 Sept 35.3 °C 36 % 49 km/h 0.0 mm Very high 39
4 Sept 35.3 °C 32 % 37 km/h 0.0 mm High 38
5 Sept 35.7 °C 30 % 45 km/h 0.0 mm Very high 43
6 Sept 34.6 °C 21 % 49 km/h 0.0 mm Very high 48
7 Sept 34.4 °C 21 % 52 km/h 0.0 mm Extreme 51
8 Sept 35.0 °C 23 % 59 km/h 0.0 mm Extreme 57
9 Sept 35.0 °C 27 % 53 km/h 0.0 mm Extreme 56
10 Sept 35.5 °C 27 % 49 km/h 0.0 mm Very high 49
11 Sept 34.9 °C 37 % 34 km/h 0.2 mm High 37
12 Sept 35.6 °C 35 % 28 km/h 0.0 mm High 37
13 Sept 36.4 °C 33 % 31 km/h 0.0 mm Very high 38
14 Sept 36.6 °C 33 % 37 km/h 0.0 mm Very high 38
15 Sept 36.3 °C 33 % 39 km/h 0.0 mm Very high 40
16 Sept 36.0 °C 28 % 45 km/h 0.0 mm Very high 42
17 Sept 36.0 °C 21 % 39 km/h 0.0 mm Very high 45
18 Sept after 35.0 °C 29 % 42 km/h 0.0 mm Very high 46
19 Sept after 34.6 °C 28 % 46 km/h 0.0 mm Very high 48
20 Sept after 34.9 °C 22 % 41 km/h 0.0 mm Very high 46
21 Sept after 37.8 °C 19 % 54 km/h 0.0 mm Extreme 58
22 Sept after 34.9 °C 11 % 49 km/h 0.0 mm Extreme 60
23 Sept after 34.0 °C 22 % 41 km/h 0.0 mm Extreme 51
24 Sept after 34.8 °C 27 % 38 km/h 0.0 mm Very high 46
25 Sept after 36.3 °C 23 % 38 km/h 0.0 mm Very high 47
26 Sept after 37.2 °C 23 % 38 km/h 0.0 mm Very high 47
27 Sept after 35.6 °C 34 % 31 km/h 0.0 mm Very high 40

Before and after, from space

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

Before · 2 Aug 2021
After · 24 Sept 2021

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 · 585Every 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 Australia ›

Frequently asked questions

How long did the West Arnhem fire last?
According to the heat detections seen by satellite inside the perimeter, it burned from 9 August 2021 to 17 September 2021 (40 days). The perimeter dates it from 15 August 2021 to 14 September 2021.
How much area did it burn?
The perimeter GWIS (Copernicus) rebuilt from heat detections is 13,824 hectares (138.2 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire only entered West Arnhem (13,898 ha, 0.3 %).
What was the weather like?
During the fire the temperature reached 36.8 °C, humidity dropped to 13 % and gusts hit 59 km/h. The fire danger index (FWI) reached 57, class Extreme.
Where does this data come from?
From the GWIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of Australia (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: 000 · Emergency number and official warnings ›

Satellite cross-check

History of this page · 2 Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.
  1. Last day with fire: 14 September 2021 → 17 September 2021.
  2. Start date: 15 August 2021 → 9 August 2021.

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 000.

How we know this
  • Perimeter: GWIS (Copernicus), rebuilt from heat detections rather than mapped on imagery.
  • Dates adjusted with the VIIRS detections inside the perimeter, which said 15 August 2021 to 14 September 2021. 585 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.

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 ADM2 (Creative Commons Attribution 4.0 International (CC BY 4.0)). 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.