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West Arnhem fire, 1 September 2023 West Arnhem

Out · last detection 23 Sept 2023, 04:46 UTC

The fire started on 1 September 2023 in West Arnhem, Australia, and satellites saw it burning for 23 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 11,365 hectares from heat detections, spread across a single municipality.

It is the 1260th largest in Northern Territory since 2016 (of 3521 with a page). Number 486 in Australia in 2023, of 1235.

Compare with…

Suggestions: West Arnhem · 2019West Arnhem · 2018West Arnhem · 2026West Arnhem · 2026

Burnt area
11,365ha
GWIS perimeter (Copernicus)
Duration
23days
1 Sept 2023 – 23 Sept 2023
Municipalities hit
1
local government areas
Started on
1 Sept
2023
Heat detections
656
in a single hotspot: 139 MW
Danger at start
46
Very high · FWI index
Average daily power
230MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 1 Sept23 Sept
23 Sept 2023

How it evolved, day by day

1 Sept 2023 · 84 MW · 19 2 Sept 2023 · 115 MW · 22 3 Sept 2023 · 82 MW · 13 4 Sept 2023 · 67 MW · 8 5 Sept 2023 · 28 MW · 7 6 Sept 2023 · 33 MW · 4 7 Sept 2023 · 727 MW · 38 8 Sept 2023 · 126 MW · 25 9 Sept 2023 · 139 MW · 17 10 Sept 2023 · 442 MW · 46 11 Sept 2023 · 291 MW · 62 12 Sept 2023 · 472 MW · 43 13 Sept 2023 · 980 MW · 92 14 Sept 2023 · 975 MW · 110 15 Sept 2023 · 95 MW · 37 16 Sept 2023 · 55 MW · 21 17 Sept 2023 · 149 MW · 37 18 Sept 2023 · 253 MW · 29 19 Sept 2023 · 20 MW · 4 20 Sept 2023 · 47 MW · 6 21 Sept 2023 · 24 MW · 4 22 Sept 2023 · 35 MW · 7 23 Sept 2023 · 47 MW · 5
1 Sept 5 Sept 9 Sept 13 Sept 17 Sept 21 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
53km/h · peak gust
20%lowest humidity

It had gone more than two months without rain (1 mm or more) when it started.

This area had burned before

95% of the perimeter overlaps earlier fires recorded since 2016: 1,812 ha in 2016, 6,429 ha in 2018, 8,461 ha in 2019, 417 ha in 2020, 1,920 ha in 2021, 1,256 ha in 2022. Part of it burned more than once, so the yearly figures add up to more than the 10,777 ha that had burned before.

How big is it?

10 km
It burned the equivalent of 7.2% of the area of London (114 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
    11,453 ha reached on 1 Sept
    0.2 %

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)
1 Sept 32.5 °C 22 % 40 km/h 0.0 mm Very high 46
2 Sept 32.9 °C 24 % 40 km/h 0.0 mm Very high 45
3 Sept 33.2 °C 22 % 29 km/h 0.0 mm Very high 42
4 Sept 33.6 °C 20 % 29 km/h 0.0 mm Very high 40
5 Sept 33.9 °C 20 % 34 km/h 0.0 mm Very high 44
6 Sept 34.7 °C 23 % 33 km/h 0.0 mm Very high 42
7 Sept 35.0 °C 25 % 30 km/h 0.0 mm Very high 40
8 Sept 34.7 °C 36 % 46 km/h 0.1 mm Very high 43
9 Sept 35.4 °C 30 % 50 km/h 0.0 mm Very high 45
10 Sept 35.1 °C 30 % 52 km/h 0.0 mm Very high 45
11 Sept 34.7 °C 24 % 53 km/h 0.0 mm Very high 48
12 Sept 32.1 °C 36 % 47 km/h 0.0 mm Very high 42
13 Sept 33.7 °C 26 % 50 km/h 0.0 mm Very high 44
14 Sept 31.7 °C 36 % 46 km/h 0.0 mm Very high 41
15 Sept 33.5 °C 23 % 50 km/h 0.0 mm Very high 49
16 Sept 31.4 °C 29 % 49 km/h 0.0 mm Very high 46
17 Sept 31.2 °C 34 % 46 km/h 0.0 mm Very high 42
18 Sept 32.1 °C 31 % 44 km/h 0.1 mm Very high 41
19 Sept 33.3 °C 28 % 38 km/h 0.0 mm Very high 39
20 Sept 35.8 °C 23 % 31 km/h 0.0 mm Very high 41
21 Sept 35.5 °C 29 % 34 km/h 0.0 mm Very high 40
22 Sept 36.7 °C 24 % 48 km/h 0.0 mm Very high 47
23 Sept 36.3 °C 23 % 41 km/h 0.0 mm Very high 46
24 Sept after 34.2 °C 25 % 40 km/h 0.0 mm Very high 45
25 Sept after 36.0 °C 22 % 39 km/h 0.0 mm Very high 43
26 Sept after 35.4 °C 23 % 46 km/h 0.0 mm Extreme 51
27 Sept after 34.9 °C 25 % 41 km/h 0.0 mm Very high 47
28 Sept after 34.9 °C 29 % 50 km/h 0.0 mm Extreme 52
29 Sept after 33.5 °C 39 % 43 km/h 0.2 mm Very high 39
30 Sept after 33.8 °C 37 % 35 km/h 0.0 mm High 35
1 Oct after 36.1 °C 29 % 36 km/h 0.0 mm High 36
2 Oct after 37.1 °C 27 % 32 km/h 0.0 mm Very high 40
3 Oct after 36.7 °C 26 % 43 km/h 0.0 mm Very high 46

Before and after, from space

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

Before · 25 Aug 2023
After · 30 Sept 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 21 September 2023 the air beside the fire reached 16 µg/m³ of PM2.5, but no daily average passed the WHO guideline (15).

PM2.5 peak16 µg/m³
Days over the guideline0 days
PM1023 µg/m³
Optical depth0.32
56789101112131415161718192021
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 · 656Every 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 1 September 2023 to 23 September 2023 (23 days). The perimeter dates it from 7 September 2023 to 18 September 2023.
How much area did it burn?
The perimeter GWIS (Copernicus) rebuilt from heat detections is 11,365 hectares (113.6 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire only entered West Arnhem (11,453 ha, 0.2 %).
What was the weather like?
During the fire the temperature reached 36.7 °C, humidity dropped to 20 % and gusts hit 53 km/h. The fire danger index (FWI) reached 49, class Very high.
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: 18 September 2023 → 23 September 2023.
  2. Start date: 7 September 2023 → 1 September 2023.

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 7 September 2023 to 18 September 2023. 656 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 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.