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Dasse fire, 29 March 2026 Dasse, Kori

Out · last detection 10 Apr 2026, 14:30 UTC

The fire started on 29 March 2026 in Dasse, Sierra Leone, and satellites saw it burning for 13 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 3,503 hectares from heat detections, spread across 2 municipalities.

It is the 27th largest in Southern since 2016 (of 393 with a page). Number 36 in Sierra Leone in 2026, of 305.

Compare with…
Burnt area
3,503ha
GWIS perimeter (Copernicus)
Duration
13days
29 Mar 2026 – 10 Apr 2026
Municipalities hit
2
chiefdoms
Started on
29 Mar
2026
Heat detections
88
in a single hotspot: 175 MW
Danger at start
15
Moderate · FWI index
Average daily power
198MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 29 Mar10 Apr
10 Apr 2026

How it evolved, day by day

29 Mar 2026 · 23 MW · 4 30 Mar 2026 · 402 MW · 21 31 Mar 2026 · 75 MW · 7 2 Apr 2026 · 18 MW · 2 3 Apr 2026 · 117 MW · 15 4 Apr 2026 · 325 MW · 8 5 Apr 2026 · 151 MW · 7 6 Apr 2026 · 16 MW · 4 8 Apr 2026 · 3 MW · 1 10 Apr 2026 · 852 MW · 19
29 Mar 31 Mar 3 Apr 5 Apr 8 Apr 10 Apr

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

The weather it burned in

36°high
37km/h · peak gust
43%lowest humidity

It had gone 13 days without rain (1 mm or more) when it started. Rain came after the fire: 1.6 mm on 11 Apr.

This area had burned before

14% of the perimeter overlaps earlier fires recorded since 2016: 498 ha in 2019.

How big is it?

10 km
It burned the equivalent of 2.2% of the area of London (35 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. Dasse where it started
    3,130 ha reached on 29 Mar
    9.0 %
  2. 396 ha reached on 29 Mar
    0.6 %

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 area3.2 ha
Residents≈ 850

Inside the perimeter there were about 3.2 hectares of built-up land and about 850 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)
29 Mar 35.6 °C 43 % 33 km/h 0.3 mm Moderate 15
30 Mar 33.4 °C 49 % 31 km/h 0.1 mm Moderate 15
31 Mar 33.5 °C 50 % 30 km/h 0.1 mm Moderate 15
1 Apr 34.9 °C 49 % 30 km/h 0.0 mm Moderate 16
2 Apr 34.3 °C 47 % 34 km/h 0.1 mm Moderate 18
3 Apr 34.2 °C 44 % 31 km/h 0.1 mm Moderate 18
4 Apr 33.6 °C 49 % 26 km/h 0.3 mm Moderate 17
5 Apr 34.2 °C 43 % 34 km/h 0.1 mm Moderate 19
6 Apr 35.0 °C 46 % 37 km/h 0.4 mm Moderate 20
7 Apr 33.9 °C 50 % 29 km/h 0.2 mm Moderate 20
8 Apr 35.5 °C 43 % 35 km/h 0.3 mm Moderate 21
9 Apr 34.1 °C 56 % 35 km/h 0.2 mm Moderate 17
10 Apr 35.2 °C 49 % 28 km/h 1.5 mm Low 11
11 Apr after 33.2 °C 53 % 28 km/h 1.6 mm Low 8

Before and after, from space

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

Before · 22 Mar 2026
After · 17 Apr 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 8 April 2026 the air beside the fire reached 76 µg/m³ of PM2.5. That day averaged 42: 2.8 times the WHO daily guideline (15).

PM2.5 peak76 µg/m³
Days over the guideline18 days
PM10140 µg/m³
Optical depth1.21
272829303112345678910111213
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 · 88Every 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 Sierra Leone ›

Frequently asked questions

How long did the Dasse fire last?
GWIS (Copernicus) dates it between 29 March 2026 and 10 April 2026: 13 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 3,503 hectares (35.0 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire entered 2 municipalities: Dasse (3,130 ha, 9.0 %); Kori (396 ha, 0.6 %).
What was the weather like?
During the fire the temperature reached 35.6 °C, humidity dropped to 43 % and gusts hit 37 km/h. The fire danger index (FWI) reached 21, class Moderate.
Where does this data come from?
From the GWIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of Sierra Leone (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. 88 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 ADM3 (Creative Commons Attribution 4.0 (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.