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Duk fire, 16 December 2025 Duk, Twic East

Out · last detection 4 Jan 2026, 11:05 UTC

The fire started on 16 December 2025 in Duk, South Sudan, and satellites saw it burning for 19 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 10,446 hectares from heat detections, spread across 2 municipalities.

It is the 111th largest in Jonglei since 2016 (of 427 with a page). Number 107 in South Sudan in 2025, of 292.

Compare with…

Suggestions: Duk · 2023Twic East · 2016Duk · 2017Duk · 2024

Burnt area
10,446ha
GWIS perimeter (Copernicus)
Duration
19days
16 Dec 2025 – 3 Jan 2026
Municipalities hit
2
counties
Started on
16 Dec
2025
Heat detections
271
in a single hotspot: 113 MW
Danger at start
46
Very high · FWI index
Average daily power
196MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 16 Dec3 Jan
4 Jan 2026

How it evolved, day by day

16 Dec 2025 · 50 MW · 6 17 Dec 2025 · 28 MW · 2 18 Dec 2025 · 145 MW · 14 19 Dec 2025 · 153 MW · 8 20 Dec 2025 · 10 MW · 4 22 Dec 2025 · 726 MW · 32 23 Dec 2025 · 4 MW · 1 24 Dec 2025 · 86 MW · 9 25 Dec 2025 · 58 MW · 5 26 Dec 2025 · 628 MW · 41 27 Dec 2025 · 673 MW · 55 28 Dec 2025 · 177 MW · 17 29 Dec 2025 · 309 MW · 25 30 Dec 2025 · 57 MW · 7 31 Dec 2025 · 17 MW · 5 4 Jan 2026 · 20 MW · 3
16 Dec 19 Dec 22 Dec 23 Dec 26 Dec 29 Dec 4 Jan

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

The weather it burned in

38°high
42km/h · peak gust
11%lowest humidity

It had gone 53 days without rain (1 mm or more) when it started.

This area had burned before

88% of the perimeter overlaps earlier fires recorded since 2016: 1,125 ha in 2016, 601 ha in 2017, 1,347 ha in 2020, 12,127 ha in 2023, 5,438 ha in 2024. Part of it burned more than once, so the yearly figures add up to more than the 9,175 ha that had burned before.

How big is it?

10 km
It burned the equivalent of 6.6% of the area of London (104 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. Duk where it started
    10,448 ha reached on 12 Dec
    1.5 %
  2. Twic East
    63 ha reached on 18 Dec
    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 area0.66 ha
Residents≈ 400

Inside the perimeter there were about 0.66 hectares of built-up land and about 400 residents (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)
16 Dec 32.9 °C 15 % 37 km/h 0.0 mm Very high 46
17 Dec 34.0 °C 15 % 29 km/h 0.0 mm Very high 42
18 Dec 33.0 °C 15 % 38 km/h 0.0 mm Very high 48
19 Dec 33.7 °C 17 % 34 km/h 0.0 mm Very high 46
20 Dec 34.9 °C 17 % 28 km/h 0.0 mm Very high 42
21 Dec 35.0 °C 17 % 28 km/h 0.0 mm Very high 43
22 Dec 34.7 °C 18 % 27 km/h 0.0 mm Very high 42
23 Dec 35.4 °C 18 % 28 km/h 0.0 mm Very high 42
24 Dec 36.9 °C 17 % 30 km/h 0.0 mm Very high 44
25 Dec 37.5 °C 17 % 28 km/h 0.0 mm Very high 43
26 Dec 36.7 °C 17 % 32 km/h 0.0 mm Very high 45
27 Dec 36.6 °C 19 % 38 km/h 0.0 mm Very high 50
28 Dec 35.4 °C 18 % 35 km/h 0.0 mm Very high 48
29 Dec 35.6 °C 12 % 30 km/h 0.0 mm Very high 46
30 Dec 34.2 °C 12 % 36 km/h 0.0 mm Extreme 51
31 Dec 34.4 °C 11 % 34 km/h 0.1 mm Extreme 50
1 Jan 36.3 °C 13 % 36 km/h 0.0 mm Extreme 51
2 Jan 34.0 °C 17 % 34 km/h 0.0 mm Extreme 52
3 Jan 37.6 °C 12 % 42 km/h 0.0 mm Extreme 56
4 Jan after 36.8 °C 16 % 39 km/h 0.0 mm Extreme 55
5 Jan after 36.3 °C 16 % 38 km/h 0.0 mm Extreme 56
6 Jan after 37.4 °C 16 % 37 km/h 0.0 mm Extreme 55
7 Jan after 37.1 °C 18 % 33 km/h 0.0 mm Extreme 52
8 Jan after 37.8 °C 16 % 38 km/h 0.0 mm Extreme 56
9 Jan after 38.2 °C 17 % 34 km/h 0.0 mm Extreme 52
10 Jan after 36.2 °C 15 % 42 km/h 0.0 mm Extreme 59
11 Jan after 36.4 °C 16 % 37 km/h 0.0 mm Extreme 56
12 Jan after 36.6 °C 17 % 37 km/h 0.0 mm Extreme 55
13 Jan after 37.5 °C 18 % 38 km/h 0.0 mm Extreme 57

Before and after, from space

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

Before · 9 Dec 2025
After · 10 Jan 2026

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 2 January 2026 the air beside the fire reached 152 µg/m³ of PM2.5. That day averaged 93: 6.2 times the WHO daily guideline (15).

PM2.5 peak152 µg/m³
Days over the guideline24 days
PM10158 µg/m³
Optical depth1.41
141516171819202122232425262728293031123456
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 · 271Every 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 South Sudan ›

Frequently asked questions

How long did the Duk fire last?
GWIS (Copernicus) dates it between 16 December 2025 and 3 January 2026: 19 days between the first and last heat detection of the perimeter.
How much area did it burn?
The perimeter GWIS (Copernicus) rebuilt from heat detections is 10,446 hectares (104.5 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire entered 2 municipalities: Duk (10,448 ha, 1.5 %); Twic East (63 ha, 0.0 %).
What was the weather like?
During the fire the temperature reached 37.6 °C, humidity dropped to 11 % and gusts hit 42 km/h. The fire danger index (FWI) reached 56, class Extreme.
Where does this data come from?
From the GWIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of South Sudan (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.

Satellite cross-check

History of this page Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.

No changes since 24 October 2026.

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.

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How we know this
  • Perimeter: GWIS (Copernicus), rebuilt from heat detections rather than mapped on imagery.
  • Dates from the perimeter: the VIIRS detections inside it did not change them. 271 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 3.0 Intergovernmental Organisations (CC BY 3.0 IGO)). 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.