Lan Sak fire, 20 February 2020 ลานสัก · Lan Sak
The fire started on 20 February 2020 in Lan Sak, Thailand, and satellites saw it burning for 11 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 2,717 hectares from heat detections, spread across a single municipality.
It is the 22th largest in Uthai Thani Province since 2016 (of 73 with a page). Number 100 in Thailand in 2020, of 457.
The power measured by the satellite is low (27.8 MW in the strongest hotspot), more typical of grass or stubble burning, or a slow surface fire, than of a large crown fire.
Compare with…
- Burnt area
- 2,717ha
- GWIS perimeter (Copernicus)
- Duration
- 11days
- 20 Feb 2020 – 1 Mar 2020
- Municipalities hit
- 1
- districts
- Started on
- 20 Feb
- 2020
- Heat detections
- 140
- in a single hotspot: 28 MW
- Danger at start
- 20
- Moderate · FWI index
- Average daily power
- 76MW
- detected power per day, on average
Where it burned
How it evolved, day by day
Fire radiative power detected each day, in megawatts, and number of hotspots. The magenta bar marks the peak day.
The weather it burned in
It had gone 30 days without rain (1 mm or more) when it started. Rain came after the fire: 1.5 mm on 4 Mar.
This area had burned before
99% of the perimeter overlaps earlier fires recorded since 2016: 2,686 ha in 2016, 604 ha in 2019. Part of it burned more than once, so the yearly figures add up to more than the 2,686 ha that had burned before.
How big is it?
London boundary: geoBoundaries · Office for National Statistics (Open Government Licence v3.0).
Bangkok boundary: geoBoundaries · OpenStreetMap, Wambacher · © OpenStreetMap contributors (ODbL 1.0).
Paris boundary: geoBoundaries · Institut national de l'information géographique et forestière (IGN-F) (Etalab Open License 2.0).
Madrid boundary: geoBoundaries · Open Data ESRI, IGN Central Registry of Cartography Area (CC BY 4.0).
This compares size, not location: both shapes are at the same scale, north up, centred on each other.
What happened to each town
-
2,734 ha reached on 20 Feb1.9 %
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 2020Inside 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) |
|---|---|---|---|---|---|
| 20 Feb | 30.4 °C | 41 % | 32 km/h | 0.0 mm | Moderate 20 |
| 21 Feb | 29.9 °C | 37 % | 40 km/h | 0.0 mm | High 23 |
| 22 Feb | 29.2 °C | 42 % | 38 km/h | 0.0 mm | High 23 |
| 23 Feb | 29.6 °C | 43 % | 34 km/h | 0.0 mm | High 22 |
| 24 Feb | 30.9 °C | 38 % | 30 km/h | 0.0 mm | High 22 |
| 25 Feb | 32.1 °C | 35 % | 32 km/h | 0.0 mm | High 24 |
| 26 Feb | 31.3 °C | 40 % | 30 km/h | 0.0 mm | High 25 |
| 27 Feb | 31.0 °C | 45 % | 35 km/h | 0.0 mm | High 25 |
| 28 Feb | 31.6 °C | 45 % | 30 km/h | 0.0 mm | High 24 |
| 29 Feb | 32.3 °C | 48 % | 28 km/h | 0.0 mm | High 23 |
| 1 Mar | 33.0 °C | 45 % | 22 km/h | 0.0 mm | High 22 |
| 2 Mar after | 32.5 °C | 46 % | 23 km/h | 0.0 mm | High 22 |
| 3 Mar after | 33.0 °C | 45 % | 25 km/h | 0.9 mm | Moderate 17 |
| 4 Mar after | 32.0 °C | 49 % | 26 km/h | 1.5 mm | Low 10 |
Before and after, from space
Drag the line to compare the same ground before the fire and after it.
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 · 140Every satellite heat detection, one by one, with time, satellite, power and coordinates.
| Date and time | Satellite | FRP (MW) | Lat | Lon |
|---|
Other fires nearby
- 20,476 haLan Sak ลานสัก3 March 2019 · 15 days · 9 km away
- 57,928 haMae Poen แม่เปิน23 March 2026 · 31 days · 13 km away
- 6,804 haLan Sak ลานสัก19 February 2020 · 14 days · 23 km away
- 6,266 haLan Sak ลานสัก13 April 2026 · 10 days · 26 km away
- 15,759 haMae Wong แม่วงก์March 2019 · 15 days · 29 km away
- 65,377 haBan Rai บ้านไร่4 March 2020 · 41 days · 39 km away
Frequently asked questions
- How long did the Lan Sak fire last?
- According to the heat detections seen by satellite inside the perimeter, it burned from 20 February 2020 to 1 March 2020 (11 days). The perimeter dates it from 21 February 2020 to 27 February 2020.
- How much area did it burn?
- The perimeter GWIS (Copernicus) rebuilt from heat detections is 2,717 hectares (27.2 km²). It is an estimate: official national figures may differ.
- Which municipalities burned?
- The fire only entered Lan Sak (2,734 ha, 1.9 %).
- What was the weather like?
- During the fire the temperature reached 32.1 °C, humidity dropped to 35 % and gusts hit 40 km/h. The fire danger index (FWI) reached 25, 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 · 2 Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.
- Last day with fire: 27 February 2020 → 1 March 2020.
- Start date: 21 February 2020 → 20 February 2020.
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
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 21 February 2020 to 27 February 2020. 140 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.
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.