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TH · Thailand · –

Lom Sak fire, 7 March 2026 หล่มสัก · Lom Sak

Out · last detection 10 Mar 2026, 18:38 UTC

The fire started on 7 March 2026 in Lom Sak, Thailand, and satellites saw it burning for 5 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 1,197 hectares from heat detections, spread across a single municipality.

Number 541 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.

The power measured by the satellite is low (3.0 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
1,197ha
GWIS perimeter (Copernicus)
Duration
5days
7 Mar 2026 – 11 Mar 2026
Municipalities hit
1
districts
Started on
7 Mar
2026
Heat detections
17
in a single hotspot: 3 MW
Danger at start
24
High · FWI index
Average daily power
6MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 7 Mar11 Mar
10 Mar 2026

How it evolved, day by day

7 Mar 2026 · 4 MW · 2 8 Mar 2026 · 5 MW · 6 9 Mar 2026 · 4 MW · 5 10 Mar 2026 · 8 MW · 4
7 Mar 8 Mar 9 Mar 10 Mar

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
36km/h · peak gust
33%lowest humidity

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

This area had burned before

82% of the perimeter overlaps earlier fires recorded since 2016: 426 ha in 2016, 237 ha in 2017, 227 ha in 2019, 47 ha in 2021, 231 ha in 2024, 436 ha in 2025. Part of it burned more than once, so the yearly figures add up to more than the 979 ha that had burned before.

How big is it?

10 km
It burned the equivalent of 0.8% of the area of London (12 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. Lom Sak หล่มสัก where it started
    1,203 ha reached on 7 Mar
    0.8 %

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 area< 0.1 ha
Residents< 20

Inside the perimeter there was no noticeable built-up land and almost nobody lived there (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 32.1 °C 34 % 26 km/h 0.0 mm High 24
8 Mar 32.9 °C 33 % 24 km/h 0.0 mm High 24
9 Mar 32.8 °C 34 % 29 km/h 0.0 mm High 27
10 Mar 31.2 °C 36 % 36 km/h 0.0 mm High 29
11 Mar 31.5 °C 36 % 22 km/h 0.0 mm High 26
12 Mar after 30.0 °C 37 % 24 km/h 0.2 mm High 26
13 Mar after 27.9 °C 41 % 33 km/h 0.0 mm High 28
14 Mar after 30.1 °C 35 % 31 km/h 0.0 mm High 27
15 Mar after 30.6 °C 35 % 25 km/h 0.0 mm High 26
16 Mar after 30.6 °C 38 % 21 km/h 0.0 mm High 25
17 Mar after 30.6 °C 44 % 20 km/h 0.0 mm High 23
18 Mar after 31.4 °C 46 % 21 km/h 0.1 mm High 23
19 Mar after 32.0 °C 40 % 26 km/h 0.3 mm High 24
20 Mar after 31.9 °C 47 % 26 km/h 0.0 mm High 24
21 Mar after 32.2 °C 44 % 24 km/h 0.9 mm Moderate 20

Before and after, from space

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

Before · 28 Feb 2026
After · 18 Mar 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 5 March 2026 the air beside the fire reached 48 µg/m³ of PM2.5. That day averaged 31: 2.1 times the WHO daily guideline (15).

PM2.5 peak48 µg/m³
Days over the guideline8 days
PM1048 µg/m³
Optical depth0.75
5 Mar7 Mar9 Mar11 Mar13 Mar
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 · 17Every 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 Lom Sak fire last?
GWIS (Copernicus) dates it between 7 March 2026 and 11 March 2026: 5 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 1,197 hectares (12.0 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire only entered Lom Sak (1,203 ha, 0.8 %).
What was the weather like?
During the fire the temperature reached 32.9 °C, humidity dropped to 33 % and gusts hit 36 km/h. The fire danger index (FWI) reached 29, 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.

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.
  • Dates from the perimeter: the VIIRS detections inside it did not change them. 17 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.