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AU · Australia · –

Roper Gulf fire, 17 May 2023 Roper Gulf, Katherine

Out · last detection 23 May 2023, 04:53 UTC

The fire started on 17 May 2023 in Roper Gulf, Australia, and satellites saw it burning for 7 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 39,338 hectares from heat detections, spread across 2 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
39,338ha
GWIS perimeter (Copernicus)
Duration
7days
17 May 2023 – 23 May 2023
Municipalities hit
2
local government areas
Started on
17 May
2023
Heat detections
1,449
in a single hotspot: 157 MW
Danger at start
39
Very high · FWI index
Average daily power
3.1GW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 17 May23 May
23 May 2023

How it evolved, day by day

17 May 2023 · 13,914 MW · 821 18 May 2023 · 3,735 MW · 318 19 May 2023 · 1,870 MW · 118 20 May 2023 · 404 MW · 45 21 May 2023 · 478 MW · 65 22 May 2023 · 819 MW · 59 23 May 2023 · 189 MW · 23
17 May 19 May 21 May 23 May

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

The weather it burned in

31°high
44km/h · peak gust
18%lowest humidity

It had gone 25 days without rain (1 mm or more) when it started.

This area had burned before

44% of the perimeter overlaps earlier fires recorded since 2016: 60 ha in 2016, 3,522 ha in 2017, 5,067 ha in 2018, 1,630 ha in 2020, 10,472 ha in 2021, 1,131 ha in 2022. Part of it burned more than once, so the yearly figures add up to more than the 17,313 ha that had burned before.

How big is it?

10 km
It burned the equivalent of 25% of the area of London (393 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. Roper Gulf where it started
    27,750 ha reached on 17 May
    0.2 %
  2. 11,788 ha reached on 17 May
    1.6 %

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)
17 May 31.3 °C 25 % 38 km/h 0.0 mm Very high 39
18 May 30.0 °C 21 % 34 km/h 0.0 mm High 38
19 May 29.5 °C 21 % 36 km/h 0.0 mm Very high 39
20 May 28.0 °C 21 % 38 km/h 0.0 mm Very high 41
21 May 26.9 °C 18 % 44 km/h 0.0 mm Very high 45
22 May 28.4 °C 19 % 41 km/h 0.0 mm Very high 44
23 May 30.1 °C 21 % 41 km/h 0.0 mm Very high 43
24 May after 29.7 °C 17 % 40 km/h 0.0 mm Very high 44
25 May after 30.4 °C 21 % 34 km/h 0.0 mm Very high 40
26 May after 30.2 °C 29 % 40 km/h 0.0 mm Very high 43
27 May after 28.4 °C 23 % 38 km/h 0.0 mm Very high 43
28 May after 26.6 °C 18 % 33 km/h 0.0 mm Very high 39
29 May after 27.2 °C 17 % 41 km/h 0.0 mm Very high 44
30 May after 28.2 °C 19 % 44 km/h 0.0 mm Very high 46
31 May after 29.6 °C 16 % 37 km/h 0.0 mm Very high 44
1 Jun after 30.8 °C 25 % 34 km/h 0.0 mm Very high 40
2 Jun after 31.5 °C 31 % 31 km/h 0.0 mm High 37

Before and after, from space

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

Before · 10 May 2023
After · 30 May 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 18 May 2023 the air beside the fire reached 103 µg/m³ of PM2.5. That day averaged 31: 2.1 times the WHO daily guideline (15).

PM2.5 peak103 µg/m³
Days over the guideline2 days
PM10148 µg/m³
Optical depth0.45
15 May17 May19 May21 May23 May
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 · 1,449Every 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 17 May 2023 to 23 May 2023 (7 days). The perimeter dates it from 17 May 2023 to 21 May 2023.
How much area did it burn?
The perimeter GWIS (Copernicus) rebuilt from heat detections is 39,338 hectares (393.4 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire entered 2 municipalities: Roper Gulf (27,750 ha, 0.2 %); Katherine (11,788 ha, 1.6 %).
What was the weather like?
During the fire the temperature reached 31.3 °C, humidity dropped to 18 % and gusts hit 44 km/h. The fire danger index (FWI) reached 45, 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 · 1 Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.
  1. Last day with fire: 21 May 2023 → 23 May 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; 2 polygons grouped in this page.
  • Dates adjusted with the VIIRS detections inside the perimeter, which said 17 May 2023 to 21 May 2023. 1,449 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.