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West Arnhem fire, 20 July 2018 West Arnhem, Unincorporated NT

Out · last detection 24 Jul 2018, 04:27 UTC

The fire started on 20 July 2018 in West Arnhem, Australia, and satellites saw it burning for 5 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 6,110 hectares from heat detections, spread across 2 municipalities.

It is the 2709th largest in Northern Territory since 2016 (of 3511 with a page). Number 724 in Australia in 2018, of 923.

Compare with…

Suggestions: West Arnhem · 2019West Arnhem · 2026West Arnhem · 2024Unincorporated NT · 2025

Burnt area
6,110ha
GWIS perimeter (Copernicus)
Duration
5days
20 Jul 2018 – 24 Jul 2018
Municipalities hit
2
local government areas
Started on
20 Jul
2018
Heat detections
154
in a single hotspot: 174 MW
Danger at start
40
Very high · FWI index
Average daily power
721MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 20 Jul24 Jul
24 Jul 2018

How it evolved, day by day

20 Jul 2018 · 2,883 MW · 83 21 Jul 2018 · 406 MW · 41 22 Jul 2018 · 144 MW · 11 23 Jul 2018 · 169 MW · 18 24 Jul 2018 · 5 MW · 1
20 Jul 21 Jul 22 Jul 23 Jul 24 Jul

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
41km/h · peak gust
12%lowest humidity

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

This area had burned before

69% of the perimeter overlaps earlier fires recorded since 2016: 69 ha in 2016, 4,652 ha in 2017. Part of it burned more than once, so the yearly figures add up to more than the 4,221 ha that had burned before.

How big is it?

10 km
It burned the equivalent of 3.9% of the area of London (61 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
    6,053 ha reached on 20 Jul
    0.1 %
  2. Unincorporated NT
    98 ha
    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 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)
20 Jul 34.5 °C 24 % 38 km/h 0.0 mm Very high 40
21 Jul 33.5 °C 17 % 41 km/h 0.0 mm Very high 46
22 Jul 32.5 °C 15 % 36 km/h 0.0 mm Very high 45
23 Jul 32.5 °C 12 % 27 km/h 0.0 mm Very high 42
24 Jul 32.6 °C 21 % 23 km/h 0.0 mm Very high 42
25 Jul after 32.7 °C 36 % 22 km/h 0.0 mm High 35
26 Jul after 33.7 °C 24 % 26 km/h 0.0 mm Very high 38
27 Jul after 32.0 °C 40 % 22 km/h 0.0 mm High 31
28 Jul after 32.5 °C 38 % 23 km/h 0.0 mm High 32
29 Jul after 32.5 °C 37 % 24 km/h 0.2 mm High 30
30 Jul after 33.9 °C 32 % 36 km/h 0.0 mm High 32
31 Jul after 33.6 °C 22 % 31 km/h 0.0 mm Very high 39
1 Aug after 33.2 °C 18 % 35 km/h 0.0 mm Very high 42
2 Aug after 31.2 °C 38 % 19 km/h 0.0 mm High 33
3 Aug after 31.8 °C 39 % 23 km/h 0.0 mm High 30

Before and after, from space

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

Before · 13 Jul 2018
After · 31 Jul 2018

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 · 154Every 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 20 July 2018 to 24 July 2018 (5 days). The perimeter dates it from 20 July 2018 to 23 July 2018.
How much area did it burn?
The perimeter GWIS (Copernicus) rebuilt from heat detections is 6,110 hectares (61.1 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire entered 2 municipalities: West Arnhem (6,053 ha, 0.1 %); Unincorporated NT (98 ha, 0.0 %).
What was the weather like?
During the fire the temperature reached 34.5 °C, humidity dropped to 12 % and gusts hit 41 km/h. The fire danger index (FWI) reached 46, 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: 23 July 2018 → 24 July 2018.

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 20 July 2018 to 23 July 2018. 154 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.