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TH · Thailand · –

Samoeng fire, 14 March 2020 สะเมิง · Samoeng, Mae Rim

Out · last detection 8 Apr 2020, 18:47 UTC

The fire started on 14 March 2020 in Samoeng, Thailand, and satellites saw it burning for 26 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 9,042 hectares from heat detections, spread across 2 municipalities.

It is the 3th largest in Chiang Mai Province since 2016 (of 319 with a page). Number 12 in Thailand in 2020, of 457.

Burnt area
9,042ha
GWIS perimeter (Copernicus)
Duration
26days
14 Mar 2020 – 8 Apr 2020
Municipalities hit
2
districts
Started on
14 Mar
2020
Heat detections
358
in a single hotspot: 54 MW
Danger at start
35
High · FWI index
Average daily power
60MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 14 Mar8 Apr
8 Apr 2020

How it evolved, day by day

14 Mar 2020 · 2 MW · 1 16 Mar 2020 · 8 MW · 1 17 Mar 2020 · 13 MW · 8 18 Mar 2020 · 2 MW · 2 20 Mar 2020 · 8 MW · 5 21 Mar 2020 · 11 MW · 4 22 Mar 2020 · 96 MW · 16 23 Mar 2020 · 7 MW · 5 24 Mar 2020 · 18 MW · 10 25 Mar 2020 · 12 MW · 6 26 Mar 2020 · 151 MW · 46 27 Mar 2020 · 382 MW · 105 28 Mar 2020 · 179 MW · 58 29 Mar 2020 · 11 MW · 3 30 Mar 2020 · 20 MW · 5 31 Mar 2020 · 19 MW · 5 1 Apr 2020 · 5 MW · 2 2 Apr 2020 · 3 MW · 2 3 Apr 2020 · 99 MW · 12 4 Apr 2020 · 92 MW · 19 5 Apr 2020 · 47 MW · 14 6 Apr 2020 · 188 MW · 11 7 Apr 2020 · 27 MW · 12 8 Apr 2020 · 40 MW · 6
14 Mar 21 Mar 27 Mar 31 Mar 5 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

40°high
36km/h · peak gust
19%lowest humidity

It had gone 10 days without rain (1 mm or more) when it started. Rain came after the fire: 6.4 mm on 14 Apr.

This area had burned before

75% of the perimeter overlaps earlier fires recorded since 2016: 5,677 ha in 2016, 540 ha in 2018, 4,087 ha in 2019. Part of it burned more than once, so the yearly figures add up to more than the 6,742 ha that had burned before.

How big is it?

10 km
It burned the equivalent of 5.7% of the area of London (90 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. Samoeng สะเมิง where it started
    9,038 ha reached on 16 Mar
    8.9 %
  2. Mae Rim แม่ริม
    225 ha reached on 14 Mar
    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 2020
Built-up area10 ha
Residents≈ 1,100

Inside the perimeter there were about 10 hectares of built-up land and about 1,100 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)
14 Mar 35.7 °C 31 % 30 km/h 0.0 mm High 35
15 Mar 37.1 °C 30 % 34 km/h 0.0 mm High 36
16 Mar 34.8 °C 46 % 31 km/h 0.4 mm High 27
17 Mar 36.4 °C 32 % 31 km/h 0.0 mm High 29
18 Mar 37.6 °C 27 % 26 km/h 0.0 mm High 32
19 Mar 36.1 °C 31 % 27 km/h 0.0 mm High 33
20 Mar 36.1 °C 30 % 36 km/h 1.2 mm High 27
21 Mar 36.1 °C 29 % 36 km/h 0.0 mm High 34
22 Mar 35.7 °C 29 % 31 km/h 1.4 mm High 24
23 Mar 35.1 °C 28 % 30 km/h 0.0 mm High 30
24 Mar 35.7 °C 27 % 35 km/h 0.0 mm High 34
25 Mar 36.4 °C 24 % 35 km/h 0.0 mm High 37
26 Mar 37.4 °C 23 % 30 km/h 0.0 mm High 37
27 Mar 37.8 °C 26 % 25 km/h 0.0 mm High 36
28 Mar 37.1 °C 28 % 36 km/h 0.0 mm Very high 39
29 Mar 38.5 °C 25 % 28 km/h 0.0 mm High 37
30 Mar 38.7 °C 31 % 27 km/h 0.0 mm High 37
31 Mar 38.8 °C 30 % 33 km/h 0.0 mm High 38
1 Apr 39.6 °C 20 % 35 km/h 0.0 mm Very high 42
2 Apr 39.3 °C 20 % 34 km/h 0.0 mm Very high 42
3 Apr 39.5 °C 19 % 30 km/h 0.0 mm Very high 40
4 Apr 38.9 °C 23 % 29 km/h 0.0 mm Very high 42
5 Apr 38.0 °C 27 % 28 km/h 0.0 mm Very high 39
6 Apr 37.6 °C 32 % 32 km/h 0.0 mm Very high 39
7 Apr 39.0 °C 22 % 28 km/h 0.0 mm Very high 38
8 Apr 37.0 °C 28 % 29 km/h 0.0 mm High 38
9 Apr after 36.9 °C 19 % 33 km/h 0.0 mm Very high 41
10 Apr after 38.3 °C 23 % 34 km/h 0.0 mm Very high 41
11 Apr after 37.1 °C 32 % 26 km/h 0.9 mm High 27
12 Apr after 37.1 °C 33 % 27 km/h 0.0 mm High 30
13 Apr after 37.3 °C 28 % 39 km/h 0.7 mm High 35
14 Apr after 32.1 °C 57 % 29 km/h 6.4 mm Very low 4

Its twins: fires that started in the same weather

It started with an FWI of 34.7, a minimum humidity of 31% and 10 days without rain. Fires in the area that started in weather like this since 2016: 63.

FWI at the start 34.7
Minimum humidity 31 %
Days without rain 10
this fire chosen twins rest of the area
Almost identicalSimilar

Outlines of the closest twins

Wiang Pa Pao fire, April 2024
2,235 ha 13 days FWI 34.4 Min. humidity 30 % 87 km away, in 2024

First rain (1 mm or more) after it ended: 4.5 mm on 10 May.

What happened to them

8 days
median duration
1,252 ha
median area
100 %
went past 1,000 ha
2.4 mm
rain at the end (median; 39 of 63 had it)

It was 7.2 times larger than the median of its twins and lasted 26 days, against 8 days.

Only 1 of its 63 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 24 of 63, 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 2.4 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

6.4 mmfirst rain
14 Apr6 days after it ended
36km/h · max. gust

It was considered over on 8 Apr, and on 14 Apr 6.4 mm fell. We do not know whether the rain or the firefighters put it out. Twins with rain when they ended: 39 of 63, with a median of 2.4 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 · 7 Mar 2020
After · 15 Apr 2020

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 · 358Every 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 Thailand

Frequently asked questions

How long did the Samoeng fire last?
According to the heat detections seen by satellite inside the perimeter, it burned from 14 March 2020 to 8 April 2020 (26 days). The perimeter dates it from 20 March 2020 to 8 April 2020.
How much area did it burn?
The perimeter GWIS (Copernicus) rebuilt from heat detections is 9,042 hectares (90.4 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire entered 2 municipalities: Samoeng (9,038 ha, 8.9 %); Mae Rim (225 ha, 0.5 %).
What was the weather like?
During the fire the temperature reached 39.6 °C, humidity dropped to 19 % and gusts hit 36 km/h. The fire danger index (FWI) reached 42, class Very high.
Where does this data come from?
From the GWIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of Thailand (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: 63. Their median duration was 8 days and their median area 1,252 ha; 100 % went past 1,000 ha. Only 1 of its 63 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 24 of 63, 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 2.4 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.

Emergency number: 199 · 191 · Emergency number and official warnings

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. Start date: 20 March 2020 → 14 March 2020.

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
What do you think is wrong?

We will only use your email to reply about this report. Privacy. This is not an emergency service: if there is a fire now, call 199 · 191.

How we know this
  • Perimeter: GWIS (Copernicus), rebuilt from heat detections rather than mapped on imagery; 2 polygons grouped in this page.
  • Dates adjusted with the VIIRS detections inside the perimeter, which said 20 March 2020 to 8 April 2020. 358 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 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.