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SL · Sierra Leone · –

Tonko Limba fire, 22 April 2023 Tonko Limba, Masungbala

Out · last detection 29 Apr 2023, 14:18 UTC

The fire started on 22 April 2023 in Tonko Limba, Sierra Leone, and satellites saw it burning for 8 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 1,904 hectares from heat detections, spread across 2 municipalities.

It is the 199th largest in Northern since 2016 (of 937 with a page). Number 37 in Sierra Leone in 2023, of 160.

Burnt area
1,904ha
GWIS perimeter (Copernicus)
Duration
8days
22 Apr 2023 – 29 Apr 2023
Municipalities hit
2
chiefdoms
Started on
22 Apr
2023
Heat detections
39
in a single hotspot: 94 MW
Danger at start
31
High · FWI index
Average daily power
189MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 22 Apr29 Apr
29 Apr 2023

How it evolved, day by day

22 Apr 2023 · 229 MW · 23 23 Apr 2023 · 187 MW · 4 24 Apr 2023 · 41 MW · 4 27 Apr 2023 · 478 MW · 6 29 Apr 2023 · 10 MW · 2
22 Apr 23 Apr 24 Apr 27 Apr 29 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

38°high
37km/h · peak gust
31%lowest humidity

It had gone 0 days without rain (1 mm or more) when it started. Rain came after the fire: 3.9 mm on 2 May.

This area had burned before

2% of the perimeter overlaps earlier fires recorded since 2016: 29 ha in 2017.

How big is it?

10 km
It burned the equivalent of 1.2% of the area of London (19 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. Tonko Limba where it started
    1,753 ha reached on 22 Apr
    2.0 %
  2. 163 ha reached on 22 Apr
    0.5 %

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 area4.6 ha
Residents≈ 2,400

Inside the perimeter there were about 4.6 hectares of built-up land and about 2,400 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)
22 Apr 38.3 °C 31 % 34 km/h 0.0 mm High 31
23 Apr 36.7 °C 36 % 36 km/h 0.2 mm High 31
24 Apr 35.7 °C 54 % 33 km/h 1.9 mm Moderate 13
25 Apr 34.3 °C 55 % 35 km/h 1.2 mm Moderate 15
26 Apr 32.2 °C 61 % 31 km/h 0.7 mm Moderate 16
27 Apr 35.3 °C 38 % 36 km/h 0.0 mm High 27
28 Apr 34.2 °C 44 % 37 km/h 0.0 mm High 28
29 Apr 33.9 °C 47 % 36 km/h 0.3 mm High 27
30 Apr after 34.2 °C 51 % 36 km/h 0.6 mm High 22
1 May after 33.3 °C 50 % 38 km/h 0.6 mm High 22
2 May after 34.0 °C 52 % 31 km/h 3.9 mm Low 7

Its twins: fires that started in the same weather

It started with an FWI of 30.6, a minimum humidity of 31% and rain the day before. Fires in the area that started in weather like this since 2016: 54.

FWI at the start 30.6
Minimum humidity 31 %
Days without rain 0
this fire chosen twins rest of the area
Almost identicalSimilar

Outlines of the closest twins

Malal Mara fire, March 2025
1,043 ha 9 days FWI 30.4 Min. humidity 32 % 70 km away, in 2025

First rain (1 mm or more) after it ended: 2.0 mm on 8 Apr.

What happened to them

9 days
median duration
1,395 ha
median area
100 %
went past 1,000 ha
3.6 mm
rain at the end (median; 52 of 54 had it)

It burned an area similar to its twins (1,904 ha against a median of 1,395 ha) and lasted 8 days, against 9 days.

In 2 of 54, 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 3.6 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

3.9 mmfirst rain
2 May3 days after it ended
37km/h · max. gust

It was considered over on 29 Apr, and on 2 May 3.9 mm fell. We do not know whether the rain or the firefighters put it out. Twins with rain when they ended: 52 of 54, with a median of 3.6 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 · 15 Apr 2023
After · 6 May 2023

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 24 April 2023 the air beside the fire reached 153 µg/m³ of PM2.5. That day averaged 60: 4.0 times the WHO daily guideline (15).

PM2.5 peak153 µg/m³
Days over the guideline8 days
PM10233 µg/m³
Optical depth1.24
20 Apr22 Apr24 Apr26 Apr
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 · 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 Tonko Limba fire last?
According to the heat detections seen by satellite inside the perimeter, it burned from 22 April 2023 to 29 April 2023 (8 days). The perimeter dates it from 22 April 2023 to 24 April 2023.
How much area did it burn?
The perimeter GWIS (Copernicus) rebuilt from heat detections is 1,904 hectares (19.0 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire entered 2 municipalities: Tonko Limba (1,753 ha, 2.0 %); Masungbala (163 ha, 0.5 %).
What was the weather like?
During the fire the temperature reached 38.3 °C, humidity dropped to 31 % and gusts hit 37 km/h. The fire danger index (FWI) reached 31, 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: 54. Their median duration was 9 days and their median area 1,395 ha; 100 % went past 1,000 ha. In 2 of 54, 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 3.6 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 · 1 Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.
  1. Last day with fire: 24 April 2023 → 29 April 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.

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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 22 April 2023 to 24 April 2023. 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 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.