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Mae Sot fire, 17 March 2026 แม่สอด · Mae Sot

Out · last detection 18 Apr 2026, 06:56 UTC

The fire started on 17 March 2026 in Mae Sot, Thailand, and satellites saw it burning for 33 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 10,792 hectares from heat detections, spread across a single municipality.

It is the 7th largest in Tak Province since 2016 (of 329 with a page). Number 60 in Thailand in 2026, of 689.

Compare with…

Suggestions: Mae Sot · 2021Mae Sot · 2026Mae Sot · 2026Myawaddy · 2026

Burnt area
10,792ha
GWIS perimeter (Copernicus)
Duration
33days
17 Mar 2026 – 18 Apr 2026
Municipalities hit
1
districts
Started on
17 Mar
2026
Heat detections
315
in a single hotspot: 31 MW
Danger at start
23
High · FWI index
Average daily power
36MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 17 Mar18 Apr
18 Apr 2026

How it evolved, day by day

17 Mar 2026 · 11 MW · 2 18 Mar 2026 · 45 MW · 8 19 Mar 2026 · 4 MW · 1 20 Mar 2026 · 20 MW · 6 22 Mar 2026 · 104 MW · 23 23 Mar 2026 · 255 MW · 58 24 Mar 2026 · 78 MW · 24 25 Mar 2026 · 11 MW · 3 27 Mar 2026 · 18 MW · 6 28 Mar 2026 · 11 MW · 7 29 Mar 2026 · 50 MW · 17 30 Mar 2026 · 10 MW · 6 31 Mar 2026 · 26 MW · 15 1 Apr 2026 · 41 MW · 10 2 Apr 2026 · 80 MW · 27 3 Apr 2026 · 100 MW · 34 4 Apr 2026 · 61 MW · 18 5 Apr 2026 · 9 MW · 2 6 Apr 2026 · 4 MW · 2 7 Apr 2026 · 20 MW · 4 8 Apr 2026 · 51 MW · 15 9 Apr 2026 · 19 MW · 11 10 Apr 2026 · 1 MW · 1 11 Apr 2026 · 4 MW · 3 12 Apr 2026 · 17 MW · 5 13 Apr 2026 · 11 MW · 3 14 Apr 2026 · 1 MW · 1 16 Apr 2026 · 2 MW · 1 17 Apr 2026 · 3 MW · 1 18 Apr 2026 · 11 MW · 1
17 Mar 23 Mar 29 Mar 3 Apr 8 Apr 13 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

37°high
46km/h · peak gust
27%lowest humidity

It had gone 3 days without rain (1 mm or more) when it started. Rain came after the fire: 1.3 mm on 21 Apr.

This area had burned before

80% of the perimeter overlaps earlier fires recorded since 2016: 1,317 ha in 2016, 3,062 ha in 2017, 2,242 ha in 2018, 1,237 ha in 2019, 1,981 ha in 2020, 2,817 ha in 2021, 660 ha in 2023, 1,357 ha in 2024, 3,321 ha in 2025. Part of it burned more than once, so the yearly figures add up to more than the 8,581 ha that had burned before.

How big is it?

10 km
It burned the equivalent of 6.8% of the area of London (108 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. Mae Sot แม่สอด where it started
    10,852 ha reached on 17 Mar
    6.8 %

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 2025
Built-up area11 ha
Residents≈ 400

Inside the perimeter there were about 11 hectares of built-up land and about 400 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)
17 Mar 33.2 °C 39 % 30 km/h 0.0 mm High 23
18 Mar 35.6 °C 28 % 28 km/h 0.0 mm High 30
19 Mar 34.9 °C 33 % 32 km/h 0.0 mm High 31
20 Mar 34.2 °C 36 % 38 km/h 0.0 mm High 34
21 Mar 35.3 °C 33 % 23 km/h 0.0 mm High 30
22 Mar 34.6 °C 41 % 38 km/h 0.0 mm High 31
23 Mar 34.9 °C 32 % 40 km/h 0.0 mm High 32
24 Mar 36.0 °C 29 % 40 km/h 0.0 mm High 35
25 Mar 36.1 °C 32 % 38 km/h 0.0 mm High 35
26 Mar 37.1 °C 31 % 37 km/h 0.0 mm High 35
27 Mar 36.3 °C 34 % 39 km/h 0.0 mm High 36
28 Mar 36.4 °C 32 % 32 km/h 0.0 mm High 33
29 Mar 35.3 °C 38 % 34 km/h 0.0 mm High 32
30 Mar 35.5 °C 39 % 36 km/h 0.5 mm High 34
31 Mar 36.3 °C 32 % 39 km/h 0.0 mm High 35
1 Apr 36.9 °C 31 % 33 km/h 0.0 mm High 33
2 Apr 37.1 °C 31 % 42 km/h 0.0 mm High 37
3 Apr 36.4 °C 33 % 41 km/h 0.0 mm High 37
4 Apr 35.2 °C 41 % 37 km/h 0.0 mm High 33
5 Apr 34.7 °C 44 % 41 km/h 0.0 mm High 33
6 Apr 35.7 °C 42 % 40 km/h 0.0 mm High 33
7 Apr 35.6 °C 39 % 44 km/h 0.0 mm High 35
8 Apr 36.0 °C 37 % 43 km/h 0.0 mm High 34
9 Apr 34.7 °C 39 % 42 km/h 0.0 mm High 34
10 Apr 36.0 °C 34 % 43 km/h 0.0 mm High 34
11 Apr 34.8 °C 41 % 46 km/h 0.0 mm High 36
12 Apr 35.9 °C 39 % 37 km/h 0.0 mm High 34
13 Apr 34.8 °C 45 % 38 km/h 0.0 mm High 31
14 Apr 36.5 °C 34 % 36 km/h 0.0 mm High 34
15 Apr 36.0 °C 30 % 43 km/h 0.0 mm High 38
16 Apr 37.3 °C 27 % 42 km/h 0.0 mm Very high 40
17 Apr 37.4 °C 32 % 40 km/h 0.0 mm Very high 40
18 Apr 36.7 °C 34 % 37 km/h 0.0 mm Very high 39
19 Apr after 35.4 °C 37 % 43 km/h 0.0 mm Very high 39
20 Apr after 35.2 °C 44 % 42 km/h 0.0 mm High 34
21 Apr after 34.3 °C 54 % 40 km/h 1.3 mm Moderate 18

Before and after, from space

Drag the line to compare the same ground before the fire and after it.

Before · 10 Mar 2026
After · 25 Apr 2026

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 · Copernicus

On 26 March 2026 the air beside the fire reached 97 µg/m³ of PM2.5. That day averaged 45: 3.0 times the WHO daily guideline (15).

PM2.5 peak97 µg/m³
Days over the guideline29 days
PM10102 µg/m³
Optical depth0.76
161718192021222324252627282930311234567891011121314
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 · 315Every 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 Mae Sot fire last?
According to the heat detections seen by satellite inside the perimeter, it burned from 17 March 2026 to 18 April 2026 (33 days). The perimeter dates it from 18 March 2026 to 11 April 2026.
How much area did it burn?
The perimeter GWIS (Copernicus) rebuilt from heat detections is 10,792 hectares (107.9 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire only entered Mae Sot (10,852 ha, 6.8 %).
What was the weather like?
During the fire the temperature reached 37.4 °C, humidity dropped to 27 % and gusts hit 46 km/h. The fire danger index (FWI) reached 40, 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.

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: 11 April 2026 → 18 April 2026.
  2. Start date: 18 March 2026 → 17 March 2026.

RSS Changes to this page

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; 4 polygons grouped in this page.
  • Dates adjusted with the VIIRS detections inside the perimeter, which said 18 March 2026 to 11 April 2026. 315 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.

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.