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Nieni fire, 19 March 2017 Sengbe, Nieni

Out · last detection 23 Mar 2017, 13:51 UTC

The fire started on 19 March 2017 in Nieni, Sierra Leone, and satellites saw it burning for 5 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 2,507 hectares from heat detections, spread across 2 municipalities.

It is the 142th largest in Northern since 2016 (of 1112 with a page). Number 27 in Sierra Leone in 2017, of 207.

Compare with…
Burnt area
2,507ha
GWIS perimeter (Copernicus)
Duration
5days
19 Mar 2017 – 23 Mar 2017
Municipalities hit
2
chiefdoms
Started on
19 Mar
2017
Heat detections
39
in a single hotspot: 152 MW
Danger at start
30
High · FWI index
Average daily power
183MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 19 Mar23 Mar
23 Mar 2017

How it evolved, day by day

19 Mar 2017 · 292 MW · 10 20 Mar 2017 · 3 MW · 1 21 Mar 2017 · 257 MW · 17 22 Mar 2017 · 40 MW · 6 23 Mar 2017 · 322 MW · 5
19 Mar 20 Mar 21 Mar 22 Mar 23 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
38km/h · peak gust
23%lowest humidity

It had gone 3 days without rain (1 mm or more) when it started. Rain came after the fire: 9.3 mm on 26 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 1.6% of the area of London (25 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. 1,272 ha reached on 21 Mar
    1.1 %
  2. Nieni where it started
    1,252 ha reached on 19 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 2015
Built-up area< 0.1 ha
Residents< 20

Inside the perimeter there was no noticeable built-up land and almost nobody lived there (GHSL 2015, 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)
19 Mar 35.7 °C 27 % 25 km/h 0.0 mm High 30
20 Mar 35.4 °C 27 % 29 km/h 0.0 mm High 30
21 Mar 37.4 °C 23 % 29 km/h 0.0 mm High 36
22 Mar 34.8 °C 36 % 38 km/h 0.2 mm High 34
23 Mar 34.2 °C 37 % 36 km/h 0.0 mm High 33
24 Mar after 36.7 °C 27 % 40 km/h 0.8 mm High 35
25 Mar after 32.1 °C 55 % 29 km/h 0.8 mm Moderate 15
26 Mar after 36.3 °C 38 % 28 km/h 9.3 mm Low 6

Before and after, from space

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

Before · 12 Mar 2017
After · 30 Mar 2017

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 · 39Every 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 Nieni fire last?
GWIS (Copernicus) dates it between 19 March 2017 and 23 March 2017: 5 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 2,507 hectares (25.1 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire entered 2 municipalities: Sengbe (1,272 ha, 1.1 %); Nieni (1,252 ha, 0.6 %).
What was the weather like?
During the fire the temperature reached 37.4 °C, humidity dropped to 23 % and gusts hit 38 km/h. The fire danger index (FWI) reached 36, 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.
  • Dates from the perimeter: the VIIRS detections inside it did not change them. 39 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 2015, 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.