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AU · Australia · –

Roper Gulf fire, 20 August 2023 Victoria Daly, Roper Gulf, West Arnhem

Out · last detection 4 Sept 2023, 16:51 UTC

The fire started on 20 August 2023 in Roper Gulf, Australia, and satellites saw it burning for 16 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 9,690 hectares from heat detections, spread across 3 municipalities.

This entry is probably a savanna fire in Australia’s tropical north, not a bushfire like those in the south of the country. Millions of hectares of northern savanna and grassland burn every year: much of it in burns lit on purpose early in the dry season (traditional fire management, parks and cattle stations), the rest in grass fires that return to the same ground every few years. This is our assumption, based on the location; it is not confirmed. That is why it is left out of the wildfire rankings.

Burnt area
9,690ha
GWIS perimeter (Copernicus)
Duration
16days
20 Aug 2023 – 4 Sept 2023
Municipalities hit
3
local government areas
Started on
20 Aug
2023
Heat detections
331
in a single hotspot: 92 MW
Danger at start
59
Extreme · FWI index
Average daily power
138MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 20 Aug4 Sept
4 Sept 2023

How it evolved, day by day

20 Aug 2023 · 8 MW · 5 21 Aug 2023 · 24 MW · 8 22 Aug 2023 · 176 MW · 23 23 Aug 2023 · 381 MW · 30 24 Aug 2023 · 145 MW · 26 25 Aug 2023 · 74 MW · 21 26 Aug 2023 · 61 MW · 21 27 Aug 2023 · 90 MW · 16 28 Aug 2023 · 400 MW · 27 29 Aug 2023 · 59 MW · 18 30 Aug 2023 · 153 MW · 30 31 Aug 2023 · 203 MW · 44 1 Sept 2023 · 280 MW · 33 2 Sept 2023 · 137 MW · 26 3 Sept 2023 · 9 MW · 2 4 Sept 2023 · 1 MW · 1
20 Aug 24 Aug 28 Aug 1 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

34°high
53km/h · peak gust
14%lowest humidity

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

This area had burned before

100% of the perimeter overlaps earlier fires recorded since 2016: 7,429 ha in 2016, 506 ha in 2017, 8,120 ha in 2018, 5,487 ha in 2019, 5,122 ha in 2020, 1,312 ha in 2021, 4,958 ha in 2022. Part of it burned more than once, so the yearly figures add up to more than the 9,723 ha that had burned before.

How big is it?

10 km
It burned the equivalent of 6.1% of the area of London (97 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. 7,667 ha reached on 23 Aug
    0.0 %
  2. Roper Gulf where it started
    1,933 ha reached on 20 Aug
    0.0 %
  3. 57 ha reached on 4 Sept
    0.0 %

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)

Started with Extreme FWI: 43 % of the area in Australia 60 days without rain: 8.2 % of the area in Australia

Day High Min. humidity Peak gust Rain Danger (FWI)
20 Aug 31.5 °C 17 % 43 km/h 0.0 mm Extreme 59
21 Aug 31.8 °C 19 % 36 km/h 0.0 mm Extreme 51
22 Aug 32.2 °C 20 % 39 km/h 0.0 mm Extreme 60
23 Aug 32.8 °C 21 % 47 km/h 0.0 mm Extreme 66
24 Aug 33.1 °C 23 % 42 km/h 0.0 mm Extreme 63
25 Aug 33.1 °C 19 % 51 km/h 0.0 mm Very extreme 70
26 Aug 32.9 °C 17 % 53 km/h 0.0 mm Very extreme 75
27 Aug 32.7 °C 22 % 51 km/h 0.0 mm Very extreme 74
28 Aug 33.4 °C 22 % 49 km/h 0.0 mm Extreme 67
29 Aug 32.9 °C 21 % 49 km/h 0.0 mm Extreme 68
30 Aug 33.2 °C 17 % 42 km/h 0.0 mm Extreme 65
31 Aug 34.1 °C 15 % 33 km/h 0.0 mm Very high 50
1 Sept 33.5 °C 14 % 39 km/h 0.0 mm Extreme 66
2 Sept 33.1 °C 17 % 33 km/h 0.0 mm Extreme 60
3 Sept 32.6 °C 18 % 22 km/h 0.0 mm Very high 42
4 Sept 33.3 °C 23 % 27 km/h 0.0 mm Very high 41
5 Sept after 34.4 °C 20 % 31 km/h 0.0 mm Very high 46
6 Sept after 34.3 °C 17 % 24 km/h 0.0 mm Very high 39
7 Sept after 35.3 °C 18 % 28 km/h 0.0 mm High 37
8 Sept after 35.8 °C 19 % 36 km/h 0.0 mm Very high 49
9 Sept after 35.6 °C 16 % 56 km/h 0.0 mm Very extreme 89
10 Sept after 35.9 °C 22 % 51 km/h 0.0 mm Very extreme 79
11 Sept after 35.4 °C 16 % 51 km/h 0.0 mm Very extreme 80
12 Sept after 34.1 °C 19 % 45 km/h 0.0 mm Very extreme 71
13 Sept after 33.5 °C 21 % 52 km/h 0.0 mm Very extreme 75
14 Sept after 33.5 °C 19 % 43 km/h 0.0 mm Extreme 65

Before and after, from space

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

Before · 13 Aug 2023
After · 11 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 3 September 2023 the air beside the fire reached 17 µg/m³ of PM2.5, but no daily average passed the WHO guideline (15).

PM2.5 peak17 µg/m³
Days over the guideline0 days
PM1025 µg/m³
Optical depth0.21
18 Aug22 Aug26 Aug30 Aug3 Sept
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 · 331Every 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 Roper Gulf fire last?
According to the heat detections seen by satellite inside the perimeter, it burned from 20 August 2023 to 4 September 2023 (16 days). The perimeter dates it from 20 August 2023 to 3 September 2023.
How much area did it burn?
The perimeter GWIS (Copernicus) rebuilt from heat detections is 9,690 hectares (96.9 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire entered 3 municipalities: Victoria Daly (7,667 ha, 0.0 %); Roper Gulf (1,933 ha, 0.0 %); West Arnhem (57 ha, 0.0 %).
What was the weather like?
During the fire the temperature reached 34.1 °C, humidity dropped to 14 % and gusts hit 53 km/h. The fire danger index (FWI) reached 75, class Very 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 · 1 Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.
  1. Last day with fire: 3 September 2023 → 4 September 2023.

RSS Changes to this page With cross-checks and a citable version

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 20 August 2023 to 3 September 2023. 331 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.
  • Probably a vegetation burn: not counted in the totals.

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.