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KH · Cambodia · –

Choam Ksant fire, 19 December 2018 Choam Ksant

Out · last measured on 22 Jan 2019

The fire started on 19 December 2018 in Choam Ksant, Cambodia, and satellites saw it burning for 35 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 6,215 hectares from heat detections, spread across a single municipality.

It is the 2th largest in Preah Vihear since 2016 (of 69 with a page). Number 3 in Cambodia in 2018, of 22.

We have the GWIS perimeter for this fire, but the VIIRS sensors did not capture it in enough detail: no day-by-day evolution, but the split by municipality is there.

Burnt area
6,215ha
GWIS perimeter (Copernicus)
Duration
35days
19 Dec 2018 – 22 Jan 2019
Municipalities hit
1
districts
Started on
19 Dec
2018
Danger at start
10
Low · FWI index

Where it burned

The weather it burned in

34°high
42km/h · peak gust
39%lowest humidity

It had gone 7 days without rain (1 mm or more) when it started.

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 3.9% of the area of London (62 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. Choam Ksant where it started
    6,255 ha
    1.6 %

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 2020
Built-up area0.25 ha
Residents≈ 30

Inside the perimeter there were about 0.25 hectares of built-up land and about 30 residents (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)

Day High Min. humidity Peak gust Rain Danger (FWI)
19 Dec 32.4 °C 49 % 28 km/h 0.0 mm Low 10
20 Dec 33.0 °C 50 % 19 km/h 0.0 mm Low 9
21 Dec 34.1 °C 46 % 20 km/h 0.0 mm Low 11
22 Dec 33.6 °C 49 % 22 km/h 0.0 mm Moderate 12
23 Dec 32.5 °C 51 % 26 km/h 0.0 mm Moderate 14
24 Dec 32.6 °C 48 % 28 km/h 0.0 mm Moderate 14
25 Dec 33.0 °C 50 % 26 km/h 0.0 mm Moderate 14
26 Dec 33.9 °C 43 % 24 km/h 0.0 mm Moderate 14
27 Dec 34.1 °C 43 % 19 km/h 0.0 mm Moderate 13
28 Dec 30.5 °C 61 % 22 km/h 9.9 mm Very low 1
29 Dec 29.9 °C 56 % 31 km/h 0.9 mm Very low 3
30 Dec 31.6 °C 54 % 42 km/h 0.0 mm Low 10
31 Dec 30.1 °C 47 % 42 km/h 0.0 mm Moderate 13
1 Jan 29.7 °C 52 % 42 km/h 0.0 mm Moderate 14
2 Jan 29.4 °C 50 % 41 km/h 0.0 mm Moderate 14
3 Jan 29.8 °C 52 % 38 km/h 0.0 mm Moderate 14
4 Jan 31.0 °C 50 % 33 km/h 0.0 mm Moderate 14
5 Jan 32.7 °C 50 % 36 km/h 0.0 mm Moderate 14
6 Jan 33.8 °C 47 % 37 km/h 0.0 mm Moderate 14
7 Jan 33.6 °C 40 % 30 km/h 0.0 mm Moderate 17
8 Jan 34.1 °C 39 % 32 km/h 0.0 mm Moderate 17
9 Jan 33.2 °C 43 % 28 km/h 0.0 mm Moderate 18
10 Jan 33.1 °C 42 % 31 km/h 0.0 mm Moderate 19
11 Jan 34.1 °C 39 % 28 km/h 0.0 mm Moderate 18
12 Jan 33.9 °C 40 % 27 km/h 0.0 mm Moderate 19
13 Jan 33.6 °C 42 % 22 km/h 0.0 mm Moderate 18
14 Jan 33.0 °C 42 % 23 km/h 0.0 mm Moderate 19
15 Jan 33.0 °C 41 % 23 km/h 0.0 mm Moderate 20
16 Jan 32.8 °C 44 % 31 km/h 0.0 mm High 23
17 Jan 32.3 °C 46 % 41 km/h 0.0 mm High 26
18 Jan 32.0 °C 45 % 32 km/h 0.0 mm High 24
19 Jan 32.9 °C 44 % 25 km/h 0.0 mm High 23
20 Jan 33.1 °C 43 % 23 km/h 0.0 mm Moderate 21
21 Jan 32.3 °C 46 % 37 km/h 0.0 mm High 26
22 Jan 32.5 °C 44 % 36 km/h 0.0 mm High 27
23 Jan after 31.3 °C 41 % 34 km/h 0.0 mm High 26
24 Jan after 31.6 °C 37 % 24 km/h 0.0 mm High 23
25 Jan after 31.9 °C 36 % 22 km/h 0.0 mm High 22
26 Jan after 30.9 °C 38 % 37 km/h 0.0 mm High 28
27 Jan after 31.1 °C 41 % 34 km/h 0.0 mm High 28
28 Jan after 31.6 °C 41 % 28 km/h 0.0 mm High 25
29 Jan after 32.7 °C 39 % 28 km/h 0.0 mm High 25
30 Jan after 32.9 °C 43 % 30 km/h 0.0 mm High 27
31 Jan after 32.7 °C 43 % 21 km/h 0.0 mm High 26
1 Feb after 33.0 °C 41 % 27 km/h 0.0 mm High 28

Its twins: fires that started in the same weather

It started with an FWI of 10.5, a minimum humidity of 49% and 7 days without rain. Fires in the area that started in weather like this since 2016: 24.

FWI at the start 10.5
Minimum humidity 49 %
Days without rain 7
this fire chosen twins rest of the area
Almost identicalSimilar

Outlines of the closest twins

Choam Ksant fire, February 2022
2,400 ha 8 days FWI 9.6 Min. humidity 49 % 37 km away, in 2022

First rain (1 mm or more) after it ended: 2.5 mm on 7 Mar.

What happened to them

15 days
median duration
2,398 ha
median area
100 %
went past 1,000 ha
2.5 mm
rain at the end (median; 9 of 24 had it)

It was 2.6 times larger than the median of its twins and lasted 35 days, against 15 days.

Only 2 of its 24 twins burned more. The weather on the first day does not explain everything: the wind in the following days, the fuel and the firefighting also count. In 15 of 24, 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 2.5 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

—first rain
—no rain in ten days
42km/h · max. gust

It was considered over on 22 Jan, and not even 1 mm fell in the following ten days: it went out without rain. Twins with rain when they ended: 9 of 24, with a median of 2.5 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 · 12 Dec 2018
After · 29 Jan 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.

Other fires nearby

All fires in Cambodia

Frequently asked questions

How long did the Choam Ksant fire last?
GWIS (Copernicus) dates it between 19 December 2018 and 22 January 2019: 35 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 6,215 hectares (62.2 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire only entered Choam Ksant (6,255 ha, 1.6 %).
What was the weather like?
During the fire the temperature reached 34.1 °C, humidity dropped to 39 % and gusts hit 42 km/h. The fire danger index (FWI) reached 27, class High.
Where does this data come from?
From the GWIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of Cambodia (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: 24. Their median duration was 15 days and their median area 2,398 ha; 100 % went past 1,000 ha. Only 2 of its 24 twins burned more. The weather on the first day does not explain everything: the wind in the following days, the fuel and the firefighting also count. In 15 of 24, 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 2.5 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
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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. No 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 ADM2 (Creative Commons Attribution 4.0 International (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.