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TH · Thailand · –

Sam Ngao fire, 23 January 2020 สามเงา · Sam Ngao

Out · last detection 4 Feb 2020, 06:16 UTC

The fire started on 23 January 2020 in Sam Ngao, Thailand, and satellites saw it burning for 13 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 1,440 hectares from heat detections, spread across a single municipality.

It is the 151th largest in Tak Province since 2016 (of 266 with a page). Number 248 in Thailand in 2020, of 457.

The power measured by the satellite is low (6.4 MW in the strongest hotspot), more typical of grass or stubble burning, or a slow surface fire, than of a large crown fire.

Burnt area
1,440ha
GWIS perimeter (Copernicus)
Duration
13days
23 Jan 2020 – 4 Feb 2020
Municipalities hit
1
districts
Started on
23 Jan
2020
Heat detections
47
in a single hotspot: 6 MW
Danger at start
28
High · FWI index
Average daily power
8MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 23 Jan4 Feb
4 Feb 2020

How it evolved, day by day

23 Jan 2020 · 2 MW · 2 24 Jan 2020 · 1 MW · 1 25 Jan 2020 · 11 MW · 5 26 Jan 2020 · 9 MW · 9 27 Jan 2020 · 13 MW · 4 28 Jan 2020 · 12 MW · 5 29 Jan 2020 · 21 MW · 15 30 Jan 2020 · 5 MW · 4 31 Jan 2020 · 1 MW · 1 4 Feb 2020 · 3 MW · 1
23 Jan 25 Jan 27 Jan 29 Jan 31 Jan

Fire radiative power detected each day, in megawatts, and number of hotspots. The magenta bar marks the peak day.

The weather it burned in

33°high
46km/h · peak gust
16%lowest humidity

It had gone 24 days without rain (1 mm or more) when it started.

This area had burned before

100% of the perimeter overlaps earlier fires recorded since 2016: 946 ha in 2016, 1,314 ha in 2017, 368 ha in 2018, 115 ha in 2019. Part of it burned more than once, so the yearly figures add up to more than the 1,447 ha that had burned before.

How big is it?

10 km
It burned the equivalent of 0.9% of the area of London (14 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. Sam Ngao สามเงา where it started
    1,446 ha reached on 23 Jan
    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 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)

Day High Min. humidity Peak gust Rain Danger (FWI)
23 Jan 32.9 °C 30 % 32 km/h 0.0 mm High 28
24 Jan 31.8 °C 26 % 39 km/h 0.0 mm High 32
25 Jan 30.5 °C 23 % 46 km/h 0.0 mm High 35
26 Jan 29.1 °C 16 % 38 km/h 0.0 mm High 37
27 Jan 28.4 °C 27 % 37 km/h 0.0 mm High 35
28 Jan 29.4 °C 20 % 20 km/h 0.0 mm High 32
29 Jan 30.3 °C 27 % 24 km/h 0.0 mm High 32
30 Jan 29.5 °C 39 % 30 km/h 0.0 mm High 28
31 Jan 30.5 °C 32 % 27 km/h 0.0 mm High 27
1 Feb 30.7 °C 33 % 26 km/h 0.0 mm High 27
2 Feb 31.4 °C 31 % 28 km/h 0.0 mm High 29
3 Feb 31.9 °C 26 % 31 km/h 0.0 mm High 31
4 Feb 31.8 °C 25 % 33 km/h 0.0 mm High 32
5 Feb after 31.7 °C 28 % 36 km/h 0.0 mm High 34
6 Feb after 31.4 °C 29 % 36 km/h 0.0 mm High 34
7 Feb after 32.8 °C 28 % 25 km/h 0.0 mm High 30
8 Feb after 31.9 °C 33 % 28 km/h 0.0 mm High 32
9 Feb after 30.2 °C 40 % 36 km/h 0.0 mm High 30
10 Feb after 30.9 °C 35 % 27 km/h 0.0 mm High 28
11 Feb after 33.5 °C 27 % 30 km/h 0.0 mm High 32
12 Feb after 33.0 °C 27 % 42 km/h 0.0 mm High 35
13 Feb after 31.6 °C 33 % 50 km/h 0.0 mm Very high 38
14 Feb after 30.3 °C 35 % 56 km/h 0.0 mm Very high 38

Its twins: fires that started in the same weather

It started with an FWI of 28.5, a minimum humidity of 30% and 24 days without rain. Fires in the area that started in weather like this since 2016: 51.

FWI at the start 28.5
Minimum humidity 30 %
Days without rain 24
this fire chosen twins rest of the area
Almost identicalSimilar

Outlines of the closest twins

Sam Ngao fire, March 2021
1,967 ha 3 days FWI 29.0 Min. humidity 31 % 27 km away, in 2021

First rain (1 mm or more) after it ended: none in the following ten days.

What happened to them

10 days
median duration
1,452 ha
median area
100 %
went past 1,000 ha
3.0 mm
rain at the end (median; 24 of 51 had it)

It burned an area similar to its twins (1,440 ha against a median of 1,452 ha) and lasted 13 days, against 10 days.

In 27 of 51, 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 3.0 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
46km/h · max. gust

It was considered over on 4 Feb, and not even 1 mm fell in the following ten days: it went out without rain. Twins with rain when they ended: 24 of 51, with a median of 3.0 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 · 16 Jan 2020
After · 11 Feb 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 · 47Every 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 Sam Ngao fire last?
According to the heat detections seen by satellite inside the perimeter, it burned from 23 January 2020 to 4 February 2020 (13 days). The perimeter dates it from 24 January 2020 to 31 January 2020.
How much area did it burn?
The perimeter GWIS (Copernicus) rebuilt from heat detections is 1,440 hectares (14.4 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire only entered Sam Ngao (1,446 ha, 0.5 %).
What was the weather like?
During the fire the temperature reached 32.9 °C, humidity dropped to 16 % and gusts hit 46 km/h. The fire danger index (FWI) reached 37, class 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: 51. Their median duration was 10 days and their median area 1,452 ha; 100 % went past 1,000 ha. In 27 of 51, 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 3.0 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 · 2 Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.
  1. Last day with fire: 31 January 2020 → 4 February 2020.
  2. Start date: 24 January 2020 → 23 January 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.
  • Dates adjusted with the VIIRS detections inside the perimeter, which said 24 January 2020 to 31 January 2020. 47 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.