Skip to content
worldfires
SL · Sierra Leone · –

Nimiyama fire, 20 March 2022 Nimiyama, Kunike

Out · last detection 26 Mar 2022, 13:57 UTC

The fire started on 20 March 2022 in Nimiyama, Sierra Leone, and satellites saw it burning for 7 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 1,206 hectares from heat detections, spread across 2 municipalities.

It is the 122th largest in Eastern since 2016 (of 209 with a page). Number 107 in Sierra Leone in 2022, of 167.

Burnt area
1,206ha
GWIS perimeter (Copernicus)
Duration
7days
20 Mar 2022 – 26 Mar 2022
Municipalities hit
2
chiefdoms
Started on
20 Mar
2022
Heat detections
16
in a single hotspot: 102 MW
Danger at start
37
High · FWI index
Average daily power
78MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 20 Mar26 Mar
26 Mar 2022

How it evolved, day by day

20 Mar 2022 · 193 MW · 4 21 Mar 2022 · 6 MW · 1 23 Mar 2022 · 7 MW · 1 24 Mar 2022 · 74 MW · 4 25 Mar 2022 · 5 MW · 1 26 Mar 2022 · 179 MW · 5
20 Mar 23 Mar 25 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

38°high
35km/h · peak gust
27%lowest humidity

It had gone more than two months without rain (1 mm or more) when it started. Rain came after the fire: 3.5 mm on 27 Mar.

This area had burned before

45% of the perimeter overlaps earlier fires recorded since 2016: 317 ha in 2016, 228 ha in 2019, 313 ha in 2021. Part of it burned more than once, so the yearly figures add up to more than the 544 ha that had burned before.

How big is it?

10 km
It burned the equivalent of 0.8% of the area of London (12 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. Nimiyama where it started
    1,161 ha reached on 20 Mar
    3.2 %
  2. 53 ha reached on 25 Mar
    0.1 %

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 2020
Built-up area< 0.1 ha
Residents< 20

Inside the perimeter there was no noticeable built-up land and almost nobody lived there (GHSL 2020, 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)

Started with 60 days without rain: 15 % of the area in Sierra Leone

Day High Min. humidity Peak gust Rain Danger (FWI)
20 Mar 34.8 °C 36 % 31 km/h 0.1 mm High 37
21 Mar 37.7 °C 30 % 34 km/h 2.5 mm High 26
22 Mar 37.9 °C 27 % 23 km/h 0.9 mm High 30
23 Mar 34.9 °C 48 % 30 km/h 0.5 mm High 28
24 Mar 36.8 °C 33 % 35 km/h 1.7 mm High 29
25 Mar 37.3 °C 33 % 24 km/h 3.5 mm Moderate 14
26 Mar 36.2 °C 39 % 30 km/h 4.2 mm Low 9
27 Mar after 34.4 °C 47 % 23 km/h 3.5 mm Low 6

Its twins: fires that started in the same weather

It started with an FWI of 36.8, a minimum humidity of 36% and more than two months without rain. Fires in the area that started in weather like this since 2016: 19.

FWI at the start 36.8
Minimum humidity 36 %
Days without rain 60+
this fire chosen twins rest of the area
Almost identicalSimilar

Outlines of the closest twins

Voinjama fire, February 2024
1,550 ha 17 days FWI 35.3 Min. humidity 36 % 178 km away, in 2024

First rain (1 mm or more) after it ended: 1.3 mm on 9 Mar.

What happened to them

11 days
median duration
1,542 ha
median area
100 %
went past 1,000 ha
2.0 mm
rain at the end (median; 18 of 19 had it)

It burned an area similar to its twins (1,206 ha against a median of 1,542 ha) and lasted 7 days, against 11 days.

In 1 of 19, 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 2.0 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

3.5 mmfirst rain
27 Marthe day after it ended
35km/h · max. gust

It was considered over on 26 Mar, and on 27 Mar 3.5 mm fell. We do not know whether the rain or the firefighters put it out. Twins with rain when they ended: 18 of 19, with a median of 2.0 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 · 13 Mar 2022
After · 2 Apr 2022

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 · 16Every 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 Nimiyama fire last?
GWIS (Copernicus) dates it between 20 March 2022 and 26 March 2022: 7 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 1,206 hectares (12.1 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire entered 2 municipalities: Nimiyama (1,161 ha, 3.2 %); Kunike (53 ha, 0.1 %).
What was the weather like?
During the fire the temperature reached 37.9 °C, humidity dropped to 27 % and gusts hit 35 km/h. The fire danger index (FWI) reached 37, 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.
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: 19. Their median duration was 11 days and their median area 1,542 ha; 100 % went past 1,000 ha. In 1 of 19, 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 2.0 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 Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.

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
What do you think is wrong?

We will only use your email to reply about this report. Privacy.

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. 16 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 2020, 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.