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Imperri fire, 12 March 2025 Imperri, Lower Banta

Out · last detection 22 Mar 2025, 14:22 UTC

The fire started on 12 March 2025 in Imperri, Sierra Leone, and satellites saw it burning for 11 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 3,070 hectares from heat detections, spread across 2 municipalities.

It is the 39th largest in Southern since 2016 (of 393 with a page). Number 9 in Sierra Leone in 2025, of 103.

Compare with…
Burnt area
3,070ha
GWIS perimeter (Copernicus)
Duration
11days
12 Mar 2025 – 22 Mar 2025
Municipalities hit
2
chiefdoms
Started on
12 Mar
2025
Heat detections
193
in a single hotspot: 192 MW
Danger at start
26
High · FWI index
Average daily power
946MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 12 Mar22 Mar
22 Mar 2025

How it evolved, day by day

12 Mar 2025 · 177 MW · 8 13 Mar 2025 · 12 MW · 1 15 Mar 2025 · 4,435 MW · 74 16 Mar 2025 · 760 MW · 19 20 Mar 2025 · 267 MW · 17 21 Mar 2025 · 195 MW · 10 22 Mar 2025 · 775 MW · 16
12 Mar 13 Mar 15 Mar 16 Mar 20 Mar 21 Mar 22 Mar

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
39km/h · peak gust
33%lowest humidity

It had gone 0 days without rain (1 mm or more) when it started. Rain came after the fire: 2.5 mm on 23 Mar.

This area had burned before

No earlier perimeters overlap this fire since 2016, when the satellite record begins.

How big is it?

10 km
It burned the equivalent of 1.9% of the area of London (31 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. Imperri where it started
    2,742 ha reached on 6 Mar
    4.4 %
  2. 348 ha reached on 10 Mar
    0.7 %

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 area4.9 ha
Residents≈ 700

Inside the perimeter there were about 4.9 hectares of built-up land and about 700 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)
12 Mar 35.3 °C 40 % 36 km/h 0.0 mm High 26
13 Mar 34.7 °C 37 % 38 km/h 0.0 mm High 28
14 Mar 35.0 °C 33 % 35 km/h 0.0 mm High 30
15 Mar 34.4 °C 33 % 36 km/h 0.0 mm High 30
16 Mar 34.3 °C 40 % 37 km/h 0.1 mm High 32
17 Mar 36.7 °C 35 % 39 km/h 0.2 mm High 33
18 Mar 34.4 °C 48 % 34 km/h 0.6 mm High 24
19 Mar 33.2 °C 50 % 30 km/h 0.5 mm High 23
20 Mar 34.2 °C 44 % 31 km/h 0.3 mm High 24
21 Mar 35.7 °C 41 % 35 km/h 0.5 mm High 27
22 Mar 33.8 °C 50 % 33 km/h 0.5 mm High 27
23 Mar after 33.8 °C 50 % 34 km/h 2.5 mm Low 10

Before and after, from space

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

Before · 5 Mar 2025
After · 29 Mar 2025

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 15 March 2025 the air beside the fire reached 91 µg/m³ of PM2.5. That day averaged 40: 2.7 times the WHO daily guideline (15).

PM2.5 peak91 µg/m³
Days over the guideline15 days
PM10130 µg/m³
Optical depth1.77
10111213141516171819202122232425
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 · 193Every 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 Imperri fire last?
GWIS (Copernicus) dates it between 12 March 2025 and 22 March 2025: 11 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 3,070 hectares (30.7 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire entered 2 municipalities: Imperri (2,742 ha, 4.4 %); Lower Banta (348 ha, 0.7 %).
What was the weather like?
During the fire the temperature reached 36.7 °C, humidity dropped to 33 % and gusts hit 39 km/h. The fire danger index (FWI) reached 33, class High.
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; 2 polygons grouped in this page.
  • Dates from the perimeter: the VIIRS detections inside it did not change them. 193 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.