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SS · South Sudan · –

Wulu fire, 23 December 2023 Wulu, Mvolo

Out · last detection 8 Jan 2024, 11:31 UTC

The fire started on 23 December 2023 in Wulu, South Sudan, and satellites saw it burning for 17 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 5,874 hectares from heat detections, spread across 2 municipalities.

It is the 94th largest in Lakes since 2016 (of 119 with a page). Number 78 in South Sudan in 2023, of 106.

Compare with…
Burnt area
5,874ha
GWIS perimeter (Copernicus)
Duration
17days
23 Dec 2023 – 8 Jan 2024
Municipalities hit
2
counties
Started on
23 Dec
2023
Heat detections
183
in a single hotspot: 182 MW
Danger at start
53
Extreme · FWI index
Average daily power
132MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 23 Dec8 Jan
8 Jan 2024

How it evolved, day by day

23 Dec 2023 · 7 MW · 1 25 Dec 2023 · 56 MW · 3 26 Dec 2023 · 6 MW · 2 27 Dec 2023 · 44 MW · 6 28 Dec 2023 · 1,227 MW · 42 29 Dec 2023 · 247 MW · 35 30 Dec 2023 · 156 MW · 33 31 Dec 2023 · 50 MW · 15 1 Jan 2024 · 37 MW · 13 2 Jan 2024 · 109 MW · 25 4 Jan 2024 · 1 MW · 1 5 Jan 2024 · 3 MW · 1 6 Jan 2024 · 1 MW · 2 7 Jan 2024 · 30 MW · 3 8 Jan 2024 · 5 MW · 1
23 Dec 28 Dec 2 Jan 6 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

37°high
35km/h · peak gust
12%lowest humidity

It had gone 18 days without rain (1 mm or more) when it started.

This area had burned before

89% of the perimeter overlaps earlier fires recorded since 2016: 1,678 ha in 2016, 1,537 ha in 2017, 4,732 ha in 2020, 955 ha in 2021, 1,320 ha in 2022. Part of it burned more than once, so the yearly figures add up to more than the 5,227 ha that had burned before.

How big is it?

10 km
It burned the equivalent of 3.7% of the area of London (59 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. Wulu where it started
    5,771 ha reached on 23 Dec
    0.5 %
  2. 138 ha reached on 26 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 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)
23 Dec 37.4 °C 20 % 29 km/h 0.0 mm Extreme 53
24 Dec 36.3 °C 18 % 35 km/h 0.0 mm Extreme 54
25 Dec 36.5 °C 15 % 33 km/h 0.0 mm Extreme 58
26 Dec 35.6 °C 19 % 31 km/h 0.0 mm Extreme 58
27 Dec 35.5 °C 21 % 32 km/h 0.0 mm Extreme 58
28 Dec 36.0 °C 21 % 27 km/h 0.0 mm Extreme 55
29 Dec 35.4 °C 18 % 30 km/h 0.0 mm Extreme 55
30 Dec 36.3 °C 18 % 28 km/h 0.0 mm Extreme 55
31 Dec 36.1 °C 17 % 34 km/h 0.0 mm Extreme 60
1 Jan 35.0 °C 17 % 22 km/h 0.0 mm Very high 48
2 Jan 36.9 °C 22 % 29 km/h 0.0 mm Extreme 58
3 Jan 36.4 °C 15 % 34 km/h 0.0 mm Extreme 60
4 Jan 36.5 °C 12 % 31 km/h 0.0 mm Extreme 61
5 Jan 34.8 °C 13 % 26 km/h 0.0 mm Extreme 56
6 Jan 35.5 °C 14 % 31 km/h 0.0 mm Extreme 62
7 Jan 34.9 °C 14 % 29 km/h 0.0 mm Extreme 64
8 Jan 36.5 °C 14 % 29 km/h 0.0 mm Extreme 61
9 Jan after 36.8 °C 15 % 29 km/h 0.0 mm Extreme 60
10 Jan after 36.9 °C 16 % 28 km/h 0.0 mm Extreme 61
11 Jan after 37.3 °C 16 % 34 km/h 0.0 mm Extreme 66
12 Jan after 36.2 °C 16 % 36 km/h 0.0 mm Extreme 68
13 Jan after 35.5 °C 16 % 22 km/h 0.0 mm Extreme 54
14 Jan after 37.5 °C 14 % 32 km/h 0.0 mm Extreme 63
15 Jan after 36.0 °C 16 % 32 km/h 0.0 mm Extreme 64
16 Jan after 35.1 °C 12 % 31 km/h 0.0 mm Extreme 65
17 Jan after 32.4 °C 15 % 29 km/h 0.0 mm Extreme 61
18 Jan after 34.2 °C 15 % 30 km/h 0.0 mm Extreme 62

Its twins: fires that started in the same weather

It started with an FWI of 53.4, a minimum humidity of 20% and 18 days without rain. Fires in the area that started in weather like this since 2016: 21.

FWI at the start 53.4
Minimum humidity 20 %
Days without rain 18
this fire chosen twins rest of the area
Almost identicalSimilar

Outlines of the closest twins

Wulu fire, December 2024
28,216 ha 33 days FWI 54.0 Min. humidity 21 % 56 km away, in 2024

First rain (1 mm or more) after it ended: none in the following ten days.

What happened to them

13 days
median duration
7,360 ha
median area
29 %
went past 10,000 ha
1.7 mm
rain at the end (median; 2 of 21 had it)

It burned an area similar to its twins (5,874 ha against a median of 7,360 ha) and lasted 17 days, against 13 days.

In 19 of 21, not even 1 mm fell in the ten days after the end: they went out without rain. In the rest, the first rainy day brought a median of 1.7 mm.

This is a bank of analogues: it shows what usually happens, not what will happen. With fewer than 15 twins we give no figures. How we calculate it

How it ended

—first rain
—no rain in ten days
35km/h · max. gust

It was considered over on 8 Jan, and not even 1 mm fell in the following ten days: it went out without rain. Twins with rain when they ended: 2 of 21, with a median of 1.7 mm.

Weather on this page: Open-Meteo.com (CC BY 4.0) · Copernicus Climate Change Service (ERA5)

How a twin is chosen

  • Same area: fires that have already ended, less than 250 km from this one, since 2016.
  • Same start: we compare the FWI on the first day, the minimum humidity that day and the run of days without rain before it. The slider sets how much they may differ.
  • Only pages with final weather data (ERA5 reanalysis) calculated in the same way as this fire’s; agricultural and grass burns and pages with data under review are left out.
  • Fires burning at the same time as this one (a week before or after) are left out: they share the same spell of weather and do not count as a precedent.
  • They are sorted by similarity, and the outlines of the first five are drawn.

How we calculate it

Before and after, from space

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

Before · 16 Dec 2023
After · 15 Jan 2024

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 5 January 2024 the air beside the fire reached 54 µg/m³ of PM2.5. That day averaged 33: 2.2 times the WHO daily guideline (15).

PM2.5 peak54 µg/m³
Days over the guideline13 days
PM1078 µg/m³
Optical depth0.66
24 Dec27 Dec30 Dec2 Jan5 Jan
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 · 183Every 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 Wulu fire last?
According to the heat detections seen by satellite inside the perimeter, it burned from 23 December 2023 to 8 January 2024 (17 days). The perimeter dates it from 26 December 2023 to 2 January 2024.
How much area did it burn?
The perimeter GWIS (Copernicus) rebuilt from heat detections is 5,874 hectares (58.7 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire entered 2 municipalities: Wulu (5,771 ha, 0.5 %); Mvolo (138 ha, 0.0 %).
What was the weather like?
During the fire the temperature reached 37.4 °C, humidity dropped to 12 % and gusts hit 35 km/h. The fire danger index (FWI) reached 64, 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.
How did the fires that started in similar weather in this area end?
Fires less than 250 km away that started since 2016 with a similar FWI, humidity and dry spell: 21. Their median duration was 13 days and their median area 7,360 ha; 29 % went past 10,000 ha. In 19 of 21, not even 1 mm fell in the ten days after the end: they went out without rain. In the rest, the first rainy day brought a median of 1.7 mm.

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 · 2 Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.
  1. Last day with fire: 2 January 2024 → 8 January 2024.
  2. Start date: 26 December 2023 → 23 December 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
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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 26 December 2023 to 2 January 2024. 183 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.