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TH · Thailand · –

Thong Pha Phum fire, 21 March 2026 ทองผาภูมิ · Sai Yok, Thong Pha Phum, Si Sawat

Out · last detection 24 Apr 2026, 19:16 UTC

The fire started on 21 March 2026 in Thong Pha Phum, Thailand, and satellites saw it burning for 35 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 74,827 hectares from heat detections, spread across 3 municipalities.

Number 3 in Thailand in 2026, of 688.

GWIS near-real-time perimeter, from the layer that changed in October 2025: this fire is not compared with fires from earlier years, because since then the GWIS layer gives more and larger perimeters.

Burnt area
74,827ha
GWIS perimeter (Copernicus)
Duration
35days
21 Mar 2026 – 24 Apr 2026
Municipalities hit
3
districts
Started on
21 Mar
2026
Heat detections
2,223
in a single hotspot: 42 MW
Danger at start
12
Moderate · FWI index
Average daily power
266MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 21 Mar24 Apr
24 Apr 2026

How it evolved, day by day

22 Mar 2026 · 17 MW · 5 23 Mar 2026 · 41 MW · 17 24 Mar 2026 · 81 MW · 28 25 Mar 2026 · 33 MW · 8 26 Mar 2026 · 57 MW · 12 27 Mar 2026 · 112 MW · 23 28 Mar 2026 · 124 MW · 37 29 Mar 2026 · 20 MW · 13 30 Mar 2026 · 10 MW · 4 31 Mar 2026 · 69 MW · 12 1 Apr 2026 · 88 MW · 16 2 Apr 2026 · 356 MW · 93 3 Apr 2026 · 501 MW · 163 4 Apr 2026 · 249 MW · 76 5 Apr 2026 · 143 MW · 27 6 Apr 2026 · 206 MW · 36 7 Apr 2026 · 553 MW · 104 8 Apr 2026 · 365 MW · 100 9 Apr 2026 · 345 MW · 112 10 Apr 2026 · 271 MW · 68 11 Apr 2026 · 156 MW · 39 12 Apr 2026 · 351 MW · 93 13 Apr 2026 · 624 MW · 135 14 Apr 2026 · 657 MW · 193 15 Apr 2026 · 267 MW · 86 16 Apr 2026 · 214 MW · 50 17 Apr 2026 · 527 MW · 97 18 Apr 2026 · 733 MW · 187 19 Apr 2026 · 873 MW · 228 20 Apr 2026 · 471 MW · 89 21 Apr 2026 · 140 MW · 25 22 Apr 2026 · 327 MW · 29 23 Apr 2026 · 63 MW · 14 24 Apr 2026 · 5 MW · 4
22 Mar 29 Mar 5 Apr 12 Apr 19 Apr

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

Fire front film How it spread from one satellite pass to the next (73 passes) and with what wind. Watch the film

The weather it burned in

37°high
44km/h · peak gust
15%lowest humidity

It had gone 0 days without rain (1 mm or more) when it started. Rain came after the fire: 11.1 mm on 25 Apr.

This area had burned before

76% of the perimeter overlaps earlier fires recorded since 2016: 20,495 ha in 2016, 12,175 ha in 2017, 4,030 ha in 2018, 19,325 ha in 2019, 20,584 ha in 2020, 11,109 ha in 2021, 271 ha in 2022, 24,434 ha in 2023, 20,160 ha in 2024, 645 ha in 2025. Part of it burned more than once, so the yearly figures add up to more than the 56,991 ha that had burned before.

How big is it?

10 km
It burned the equivalent of 47% of the area of London (748 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. Sai Yok ไทรโยค
    41,449 ha reached on 23 Mar
    16 %
  2. Thong Pha Phum ทองผาภูมิ where it started
    26,505 ha reached on 22 Mar
    6.8 %
  3. Si Sawat ศรีสวัสดิ์
    7,927 ha reached on 22 Mar
    2.6 %

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 2025
Built-up area17 ha
Residents≈ 1,400

Inside the perimeter there were about 17 hectares of built-up land and about 1,400 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)
7 Mar 32.5 °C 38 % 26 km/h 1.2 mm Moderate 12
8 Mar 34.1 °C 31 % 24 km/h 0.4 mm Moderate 19
9 Mar 33.9 °C 32 % 35 km/h 0.0 mm High 23
10 Mar 32.9 °C 33 % 42 km/h 0.0 mm High 26
11 Mar 33.7 °C 33 % 25 km/h 0.0 mm High 23
12 Mar 32.4 °C 37 % 28 km/h 0.0 mm High 22
13 Mar 30.5 °C 44 % 35 km/h 0.0 mm High 23
14 Mar 31.8 °C 39 % 36 km/h 0.0 mm High 24
15 Mar 32.3 °C 37 % 29 km/h 0.2 mm High 22
16 Mar 32.2 °C 40 % 22 km/h 0.8 mm Moderate 16
17 Mar 33.3 °C 37 % 44 km/h 1.1 mm Moderate 20
18 Mar 33.2 °C 43 % 27 km/h 4.8 mm Very low 5
19 Mar 33.7 °C 37 % 37 km/h 0.5 mm Moderate 17
20 Mar 34.5 °C 38 % 30 km/h 1.2 mm Moderate 15
21 Mar 34.3 °C 38 % 32 km/h 0.1 mm High 22
22 Mar 32.9 °C 43 % 30 km/h 0.4 mm Moderate 21
23 Mar 34.0 °C 36 % 31 km/h 0.0 mm High 23
24 Mar 34.6 °C 32 % 32 km/h 0.0 mm High 25
25 Mar 35.2 °C 33 % 31 km/h 0.0 mm High 26
26 Mar 35.7 °C 31 % 32 km/h 0.0 mm High 28
27 Mar 35.5 °C 27 % 30 km/h 0.0 mm High 29
28 Mar 36.5 °C 26 % 27 km/h 0.0 mm High 28
29 Mar 32.9 °C 40 % 29 km/h 0.5 mm High 26
30 Mar 35.0 °C 36 % 30 km/h 0.0 mm High 27
31 Mar 35.8 °C 24 % 31 km/h 0.0 mm High 34
1 Apr 35.6 °C 30 % 31 km/h 0.0 mm High 34
2 Apr 36.8 °C 25 % 42 km/h 0.0 mm High 36
3 Apr 36.2 °C 27 % 35 km/h 0.0 mm High 38
4 Apr 35.3 °C 30 % 37 km/h 0.0 mm Very high 40
5 Apr 34.9 °C 38 % 33 km/h 0.0 mm High 34
6 Apr 36.0 °C 28 % 31 km/h 0.0 mm High 33
7 Apr 34.8 °C 33 % 39 km/h 0.2 mm High 38
8 Apr 35.7 °C 26 % 36 km/h 0.0 mm High 37
9 Apr 35.0 °C 31 % 35 km/h 0.0 mm High 38
10 Apr 35.7 °C 28 % 34 km/h 0.0 mm High 37
11 Apr 34.0 °C 40 % 36 km/h 0.1 mm High 34
12 Apr 35.8 °C 33 % 32 km/h 0.0 mm High 33
13 Apr 35.2 °C 27 % 36 km/h 0.0 mm High 38
14 Apr 36.8 °C 18 % 33 km/h 0.0 mm Very high 45
15 Apr 36.3 °C 27 % 34 km/h 0.0 mm Very high 44
16 Apr 36.6 °C 18 % 31 km/h 0.0 mm Very high 42
17 Apr 36.9 °C 15 % 33 km/h 0.0 mm Very high 46
18 Apr 37.4 °C 18 % 35 km/h 0.0 mm Very high 48
19 Apr 36.8 °C 25 % 37 km/h 0.0 mm Very high 49
20 Apr 36.0 °C 26 % 36 km/h 0.0 mm Very high 47
21 Apr 35.7 °C 30 % 40 km/h 0.0 mm Very high 46
22 Apr 36.2 °C 32 % 37 km/h 0.2 mm Very high 45
23 Apr 36.5 °C 35 % 39 km/h 0.2 mm Very high 40
24 Apr 36.6 °C 28 % 30 km/h 0.0 mm High 37
25 Apr after 35.9 °C 42 % 34 km/h 11.1 mm Low 6

Before and after, from space

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

Before · 14 Mar 2026
After · 1 May 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 12 April 2026 the air beside the fire reached 92 µg/m³ of PM2.5. That day averaged 49: 3.2 times the WHO daily guideline (15).

PM2.5 peak92 µg/m³
Days over the guideline38 days
PM10109 µg/m³
Optical depth1.28
19 Mar27 Mar4 Apr12 Apr20 Apr
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 · 2,223Every 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 Thong Pha Phum fire last?
GWIS (Copernicus) dates it between 21 March 2026 and 24 April 2026: 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 74,827 hectares (748.3 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire entered 3 municipalities: Sai Yok (41,449 ha, 16 %); Thong Pha Phum (26,505 ha, 6.8 %); Si Sawat (7,927 ha, 2.6 %).
What was the weather like?
During the fire the temperature reached 37.4 °C, humidity dropped to 15 % and gusts hit 44 km/h. The fire danger index (FWI) reached 49, 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 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
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; 14 polygons grouped in this page.
  • Dates from the perimeter: the VIIRS detections inside it did not change them. 2,223 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.