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SL · Sierra Leone · –

Diang fire, 13 March 2019 Diang

Out · last detection 16 Mar 2019, 14:35 UTC

The fire started on 13 March 2019 in Diang, Sierra Leone, and satellites saw it burning for 5 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 1,165 hectares from heat detections, spread across a single municipality.

It is the 667th largest in Northern since 2016 (of 937 with a page). Number 133 in Sierra Leone in 2019, of 180.

Compare with…
Burnt area
1,165ha
GWIS perimeter (Copernicus)
Duration
5days
13 Mar 2019 – 17 Mar 2019
Municipalities hit
1
chiefdoms
Started on
13 Mar
2019
Heat detections
27
in a single hotspot: 44 MW
Danger at start
48
Very high · FWI index
Average daily power
116MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 13 Mar17 Mar
16 Mar 2019

How it evolved, day by day

13 Mar 2019 · 87 MW · 3 14 Mar 2019 · 192 MW · 9 15 Mar 2019 · 176 MW · 9 16 Mar 2019 · 10 MW · 6
13 Mar 14 Mar 15 Mar 16 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

39°high
37km/h · peak gust
17%lowest humidity

It had gone more than two months without rain (1 mm or more) when it started. Rain came after the fire: 10.9 mm on 21 Mar.

This area had burned before

11% of the perimeter overlaps earlier fires recorded since 2016: 128 ha in 2016.

How big is it?

10 km
It burned the equivalent of 0.7% 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. Diang where it started
    1,172 ha reached on 13 Mar
    1.1 %

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)
13 Mar 38.4 °C 19 % 36 km/h 0.0 mm Very high 48
14 Mar 38.1 °C 17 % 34 km/h 0.0 mm Very high 48
15 Mar 38.4 °C 19 % 37 km/h 0.0 mm Very high 50
16 Mar 38.8 °C 17 % 31 km/h 0.0 mm Very high 49
17 Mar 38.8 °C 18 % 37 km/h 0.0 mm Extreme 51
18 Mar after 38.2 °C 20 % 32 km/h 0.0 mm Very high 49
19 Mar after 38.2 °C 23 % 38 km/h 0.0 mm Extreme 52
20 Mar after 35.9 °C 33 % 32 km/h 0.1 mm Very high 40
21 Mar after 37.0 °C 36 % 30 km/h 10.9 mm Low 9

Its twins: fires that started in the same weather

It started with an FWI of 47.6, a minimum humidity of 19% and more than two months without rain. Fires in the area that started in weather like this since 2016: 19.

FWI at the start 47.6
Minimum humidity 19 %
Days without rain 60+
this fire chosen twins rest of the area
Almost identicalSimilar

Outlines of the closest twins

Nieni fire, March 2025
2,564 ha 16 days FWI 48.5 Min. humidity 19 % 52 km away, in 2025

First rain (1 mm or more) after it ended: 8.3 mm on 24 Mar.

What happened to them

13 days
median duration
2,092 ha
median area
100 %
went past 1,000 ha
3.1 mm
rain at the end (median; 8 of 19 had it)

It stayed below its twins: 1,165 ha against a median of 2,092 ha. It lasted 5 days, against 13 days.

In 11 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 3.1 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

10.9 mmfirst rain
21 Mar4 days after it ended
37km/h · max. gust

It was considered over on 17 Mar, and on 21 Mar 10.9 mm fell. We do not know whether the rain or the firefighters put it out. Twins with rain when they ended: 8 of 19, with a median of 3.1 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 · 6 Mar 2019
After · 24 Mar 2019

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 · 27Every 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 Diang fire last?
According to the heat detections seen by satellite inside the perimeter, it burned from 13 March 2019 to 17 March 2019 (5 days). The perimeter dates it from 13 March 2019 to 16 March 2019.
How much area did it burn?
The perimeter GWIS (Copernicus) rebuilt from heat detections is 1,165 hectares (11.6 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire only entered Diang (1,172 ha, 1.1 %).
What was the weather like?
During the fire the temperature reached 38.8 °C, humidity dropped to 17 % and gusts hit 37 km/h. The fire danger index (FWI) reached 51, class Extreme.
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 13 days and their median area 2,092 ha; 100 % went past 1,000 ha. In 11 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 3.1 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: 16 March 2019 → 17 March 2019.

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 13 March 2019 to 16 March 2019. 27 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.