Burned area
satellite only1,446ha
Perimeter published by GWIS (Copernicus).
- Source
- GWIS (Copernicus)
- Date
- 10 Mar 2023 – 21 Mar 2023
+− cross-check
No official record is matched to this page to compare it with.
LR · Liberia · –
Kolahun fire, 10 March 2023 Kolahun, Voinjama
Out · last detection 21 Mar 2023, 14:49 UTC
The fire started on 10 March 2023 in Kolahun, Liberia, and satellites saw it burning for 12 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 1,446 hectares from heat detections, spread across 2 municipalities.
It is the 93th largest in Lofa since 2016 (of 202 with a page). Number 7 in Liberia in 2023, of 29.
Use this data
Compare with…
Use this data
Fire page data · version 2026-10-27matches the official recordwith caveatssatellite onlymodel
When copying, the sentence is
Tick the figures you want: they make up the lede and the CSV.
Duration by satellite
satellite only12days
10 Mar 2023 to 21 Mar 2023: first and last day with fire on the page.
- Source
- GWIS (Copernicus) · NASA FIRMS · VIIRS
- Date
- last detection: 21 Mar 2023, 14:49 UTC
+− cross-check
Satellites pass a few times a day and cloud or smoke can hide the fire: a lack of detections is not an official extinction. Each country’s emergency service declares a fire contained or out.
Start
satellite only10 Mar 2023
First day with fire seen by the satellites or the perimeter.
- Source
- GWIS (Copernicus) · NASA FIRMS · VIIRS
- Date
- 10 Mar 2023
+− cross-check
No official record is matched to this page, so the alert time and the cause are not known here.
Hotspots
satellite only34
VIIRS detections at 375 m. Most intense hotspot: 68 MW.
- Source
- NASA FIRMS · VIIRS (Suomi NPP)
- Date
- 10 Mar 2023 – 21 Mar 2023
+− cross-check
There is no official record to compare with. Each hotspot is a pixel detected in one satellite pass, not a separate fire.
The worst day
satellite only205MW
Total radiative power on 19 March 2023; hotspots that day: 8.
- Source
- NASA FIRMS · VIIRS (FRP)
- Date
- 19 Mar 2023
+− cross-check
Fire radiative power (FRP) measures the energy the fire gives off when the satellite passes. Added up by day, it compares intensity, not area.
Danger at the start
model17.8FWI · moderate
Fire Weather Index (Canadian system) computed by WorldFires for the day the fire started. Consecutive days without rain before: 3.
- Source
- WorldFires calculation (Canadian FWI system)
- Date
- 10 Mar 2023, local noon
- Model
- ERA5 0,25° (ECMWF · Copernicus C3S) · Open-Meteo.com
+− cross-check
This is an index computed from weather model data, not a measurement of the fire nor an official warning. Danger warnings are issued by each country’s authority. Emergency number and official warnings
Weather during the fire
model34.2°C · 41% RH
High of 34.2 °C and minimum humidity of 41% on 12 March 2023; gusts of 30 km/h on 19 March 2023.
- Source
- weather model at the fire’s grid cell
- Date
- 10 Mar 2023 – 21 Mar 2023
- Model
- ERA5 0,25° (ECMWF · Copernicus C3S) · Open-Meteo.com
+− cross-check
These are model values for a cell of about 25 km, not from a weather station: they may differ from what was measured on the ground.
Living inside
model≈ 50people
Estimated residents inside the perimeter and 0.17 ha of built-up area (100 m grid, epoch 2025).
- Source
- GHSL R2023A · JRC
- Date
- calculated on 24 October 2026
+− cross-check
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.
This page’s change log has been kept since 24 October 2026: every night what it publishes is compared and the difference is logged. Anything earlier is reconstructed from each source’s date and marked as reconstructed.
Show
-
· reconstructed weatherWeather and FWI computed from the ERA5 reanalysis
-
logLast day with fire: 14 March 2023 → 21 March 2023.
-
logStart date: 13 March 2023 → 10 March 2023.
-
· reconstructed GHSLPopulation and built-up area computed
What was saved on 27 October 2026
Every night a snapshot of what the page shows is saved. If anything changes, it appears in the list as a log entry.
- Area
- 1,446 ha
- Dates
- 10 Mar 2023 – 21 Mar 2023
- Name
- Kolahun
- Official record
- —
Versioned permanent link
https://worldfires.org/en/fire/kolahun-2023-03-4?v=2026-10-27A version keeps the area, dates, name and official record; the area as it was logged (changes under 2% are not logged). The map, hotspots and weather always show today’s data.
Citation
A lede of about 60 words figures only, no adjectives
CSV for this fire kolahun-2023-03-4.csv · daily, no individual hotspots
| fecha | focos_viirs | frp_mw | tmax_c | tmin_c | hr_min_pct | viento_max_kmh | racha_max_kmh | precip_mm | fwi | clase_fwi | dentro_del_incendio |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 2023-03-10 | 0 | 0 | 33.5 | 20.5 | 41 | 13.2 | 24.5 | 0 | 17.8 | moderado | 1 |
| 2023-03-11 | 0 | 0 | 32.5 | 21.6 | 46 | 12 | 27.7 | 0 | 16.6 | moderado | 1 |
| 2023-03-12 | 3 | 106 | 34.2 | 22.2 | 41 | 13.2 | 28.8 | 0.6 | 16.4 | moderado | 1 |
| 2023-03-13 | 10 | 189 | 33.5 | 23.2 | 46 | 10.8 | 24.8 | 1.4 | 10 | bajo | 1 |
| 2023-03-14 | 7 | 82 | 33.3 | 22.1 | 48 | 10.6 | 25.2 | 16 | 1.3 | muy_bajo | 1 |
| 2023-03-15 | 0 | 0 | 29.8 | 20.1 | 66 | 9 | 24.5 | 5.3 | 0.5 | muy_bajo | 1 |
| 2023-03-16 | 0 | 0 | 32.9 | 21.3 | 52 | 12.3 | 27 | 4.9 | 0.8 | muy_bajo | 1 |
| 2023-03-17 | 1 | 14 | 32.2 | 21 | 50 | 10.1 | 28.1 | 0.1 | 4.2 | muy_bajo | 1 |
| 2023-03-18 | 4 | 26 | 32.7 | 21.2 | 42 | 14.2 | 28.4 | 0 | 9.7 | bajo | 1 |
| 2023-03-19 | 8 | 205 | 32.3 | 20 | 42 | 14.2 | 29.5 | 0 | 11.2 | moderado | 1 |
| 2023-03-20 | 0 | 0 | 33.2 | 21.5 | 40 | 13.2 | 26.6 | 0 | 12.4 | moderado | 1 |
| 2023-03-21 | 1 | 31 | 32.7 | 21.2 | 47 | 13 | 26.6 | 0.2 | 13.1 | moderado | 1 |
| 2023-03-22 | 0 | 0 | 32.1 | 21.9 | 49 | 12.5 | 28.1 | 1.8 | 5.8 | bajo | 0 |
It is generated in your browser from this page’s data: one file per fire, aggregated by day and without individual hotspots.
Live widget for your story
It updates itself while the fire is still active and links to this page. Free, with the attribution shown at the bottom.
Sources for this page: GWIS (Copernicus), NASA FIRMS (VIIRS), ERA5 (ECMWF/Copernicus C3S) · Open-Meteo.com (CC BY 4.0), GHSL (JRC). Open-Meteo.com · How we build fire pages: methodology
- Burnt area
- 1,446ha
- GWIS perimeter (Copernicus)
- Duration
- 12days
- 10 Mar 2023 – 21 Mar 2023
- Municipalities hit
- 2
- districts
- Started on
- 10 Mar
- 2023
- Heat detections
- 34
- in a single hotspot: 68 MW
- Danger at start
- 18
- Moderate · FWI index
- Average daily power
- 93MW
- detected power per day, on average
Where it burned
HOTSPOTS BY DAY
10 Mar21 Mar
21 Mar 2023
How it evolved, day by day
12 Mar
14 Mar
19 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
34°high
30km/h · peak gust
40%lowest humidity
It had gone 3 days without rain (1 mm or more) when it started. Rain came after the fire: 1.8 mm on 22 Mar.
This area had burned before
28% of the perimeter overlaps earlier fires recorded since 2016: 18 ha in 2017, 332 ha in 2018, 60 ha in 2019.
How big is it?
London boundary: geoBoundaries · Office for National Statistics (Open Government Licence v3.0).
Paris boundary: geoBoundaries · Institut national de l'information géographique et forestière (IGN-F) (Etalab Open License 2.0).
Madrid boundary: geoBoundaries · Open Data ESRI, IGN Central Registry of Cartography Area (CC BY 4.0).
Berlin boundary: geoBoundaries · Federal Agency for Cartography and Geodesy (dl-de/by-2-0).
This compares size, not location: both shapes are at the same scale, north up, centred on each other.
What happened to each town
-
Kolahun where it started1,004 ha reached on 12 Mar0.4 %
-
452 ha reached on 13 Mar0.2 %
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 2025Built-up area0.17 ha
Residents≈ 50
Inside the perimeter there were about 0.17 hectares of built-up land and about 50 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) |
|---|---|---|---|---|---|
| 10 Mar | 33.5 °C | 41 % | 24 km/h | 0.0 mm | Moderate 18 |
| 11 Mar | 32.5 °C | 46 % | 28 km/h | 0.0 mm | Moderate 17 |
| 12 Mar | 34.2 °C | 41 % | 29 km/h | 0.6 mm | Moderate 16 |
| 13 Mar | 33.5 °C | 46 % | 25 km/h | 1.4 mm | Low 10 |
| 14 Mar | 33.3 °C | 48 % | 25 km/h | 16.0 mm | Very low 1 |
| 15 Mar | 29.8 °C | 66 % | 24 km/h | 5.3 mm | Very low 0 |
| 16 Mar | 32.9 °C | 52 % | 27 km/h | 4.9 mm | Very low 1 |
| 17 Mar | 32.2 °C | 50 % | 28 km/h | 0.1 mm | Very low 4 |
| 18 Mar | 32.7 °C | 42 % | 28 km/h | 0.0 mm | Low 10 |
| 19 Mar | 32.3 °C | 42 % | 30 km/h | 0.0 mm | Moderate 11 |
| 20 Mar | 33.2 °C | 40 % | 27 km/h | 0.0 mm | Moderate 12 |
| 21 Mar | 32.7 °C | 47 % | 27 km/h | 0.2 mm | Moderate 13 |
| 22 Mar after | 32.1 °C | 49 % | 28 km/h | 1.8 mm | Low 6 |
Its twins: fires that started in the same weather
It started with an FWI of 17.8, a minimum humidity of 41% and 3 days without rain. Fires in the area that started in weather like this since 2016: 15.
FWI at the start
17.8
Minimum humidity
41 %
Days without rain
3
this fire
chosen twins
rest of the area
Almost identicalSimilar
Outlines of the closest twins
This fire · Kolahun fire, 10 March 2023
1,446 ha
12 days
FWI 17.8
Min. humidity 41 %
Quardu Boundi fire, February 2020
1,519 ha
15 days
FWI 19.0
Min. humidity 40 %
41 km away, in 2020
First rain (1 mm or more) after it ended: 9.3 mm on 11 Mar.
Badjia fire, April 2016
1,764 ha
12 days
FWI 18.0
Min. humidity 41 %
162 km away, in 2016
First rain (1 mm or more) after it ended: 1.9 mm on 15 Apr.
Nimikoro fire, April 2022
1,121 ha
14 days
FWI 18.8
Min. humidity 41 %
128 km away, in 2022
First rain (1 mm or more) after it ended: 2.2 mm on 27 Apr.
Sandor fire, April 2022
3,001 ha
12 days
FWI 18.6
Min. humidity 41 %
140 km away, in 2022
First rain (1 mm or more) after it ended: 4.4 mm on 23 Apr.
Niawa Lenga fire, April 2016
1,953 ha
8 days
FWI 18.0
Min. humidity 41 %
175 km away, in 2016
First rain (1 mm or more) after it ended: 1.4 mm on 10 Apr.
What happened to them
- 8 days
- median duration
- 1,372 ha
- median area
- 100 %
- went past 1,000 ha
- 2.2 mm
- rain at the end (median; 15 of 15 had it)
It burned an area similar to its twins (1,446 ha against a median of 1,372 ha) and lasted 12 days, against 8 days.
All of them had rain in the ten days after the end: the first rainy day brought a median of 2.2 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
1.8 mmfirst rain
22 Marthe day after it ended
30km/h · max. gust
It was considered over on 21 Mar, and on 22 Mar 1.8 mm fell. We do not know whether the rain or the firefighters put it out. Twins with rain when they ended: 15 of 15, with a median of 2.2 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.
Before and after, from space
Drag the line to compare the same ground before the fire and after it.
↔
Before · 3 Mar 2023
After · 28 Mar 2023
Sentinel-2 did not pass over on that day. Try another date, or use false colour, which is daily.
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 · CopernicusOn 14 March 2023 the air beside the fire reached 630 µg/m³ of PM2.5. That day averaged 214: 14 times the WHO daily guideline (15).
PM2.5 peak630 µg/m³
Days over the guideline7 days
PM10900 µg/m³
Optical depth3.34
WHO 15
11 Mar13 Mar15 Mar17 Mar
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 · 34Every 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 time | Satellite | FRP (MW) | Lat | Lon |
|---|
Other fires nearby
Frequently asked questions
- How long did the Kolahun fire last?
- According to the heat detections seen by satellite inside the perimeter, it burned from 10 March 2023 to 21 March 2023 (12 days). The perimeter dates it from 13 March 2023 to 14 March 2023.
- How much area did it burn?
- The perimeter GWIS (Copernicus) rebuilt from heat detections is 1,446 hectares (14.5 km²). It is an estimate: official national figures may differ.
- Which municipalities burned?
- The fire entered 2 municipalities: Kolahun (1,004 ha, 0.4 %); Voinjama (452 ha, 0.2 %).
- What was the weather like?
- During the fire the temperature reached 34.2 °C, humidity dropped to 40 % and gusts hit 30 km/h. The fire danger index (FWI) reached 18, class Moderate.
- Where does this data come from?
- From the GWIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of Liberia (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: 15. Their median duration was 8 days and their median area 1,372 ha; 100 % went past 1,000 ha. All of them had rain in the ten days after the end: the first rainy day brought a median of 2.2 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 · 2 Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.
- Last day with fire: 14 March 2023 → 21 March 2023.
- Start date: 13 March 2023 → 10 March 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.
Report an error
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 2023 to 14 March 2023. 34 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.
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 ADM2 (Creative Commons Attribution 3.0 Intergovernmental Organisations (CC BY 3.0 IGO)). 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.