Dan Sai fire, February 2023 ด่านซ้าย · Dan Sai
The fire started on 25 February 2023 in Dan Sai, Thailand, and satellites saw it burning for 16 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 1,466 hectares from heat detections, spread across a single municipality.
It is the 62th largest in Loei Province since 2016 (of 113 with a page). Number 193 in Thailand in 2023, of 369.
The power measured by the satellite is low (11.4 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
- 1,466ha
- GWIS perimeter (Copernicus)
- Duration
- 16days
- 25 Feb 2023 – 12 Mar 2023
- Municipalities hit
- 1
- districts
- Started on
- 25 Feb
- 2023
- Heat detections
- 43
- in a single hotspot: 11 MW
- Danger at start
- 20
- Moderate · FWI index
- Average daily power
- 36MW
- 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 23 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: 1,261 ha in 2016, 887 ha in 2017, 1,265 ha in 2018, 1,380 ha in 2019, 1,183 ha in 2020, 1,150 ha in 2021, 252 ha in 2022. Part of it burned more than once, so the yearly figures add up to more than the 1,474 ha that had burned before.
- 1,380 ha Dan Sai fire, March 2019 4,640 ha in total; the hectares shown are those it shares with this fire
- 1,261 ha Dan Sai fire, March 2016 6,404 ha in total; the hectares shown are those it shares with this fire
- 1,177 ha Dan Sai fire, March 2018 2,046 ha in total; the hectares shown are those it shares with this fire
- 1,085 ha Dan Sai fire, March 2021 2,011 ha in total; the hectares shown are those it shares with this fire
- 1,075 ha Dan Sai fire, February 2020 1,577 ha in total; the hectares shown are those it shares with this fire
- 108 ha Dan Sai fire, February 2020 1,537 ha in total; the hectares shown are those it shares with this fire
- 88 ha Dan Sai fire, March 2018 1,102 ha in total; the hectares shown are those it shares with this fire
- 65 ha Dan Sai fire, February 2021 1,336 ha in total; the hectares shown are those it shares with this fire
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
-
1,474 ha reached on 28 Feb1.1 %
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.
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) |
|---|---|---|---|---|---|
| 28 Feb | 29.8 °C | 35 % | 22 km/h | 0.0 mm | Moderate 20 |
| 1 Mar | 32.3 °C | 34 % | 24 km/h | 0.0 mm | Moderate 21 |
| 2 Mar | 30.1 °C | 43 % | 30 km/h | 0.0 mm | High 22 |
| 3 Mar | 29.7 °C | 40 % | 23 km/h | 0.0 mm | Moderate 21 |
| 4 Mar | 28.7 °C | 44 % | 30 km/h | 0.0 mm | Moderate 21 |
| 5 Mar | 28.6 °C | 47 % | 25 km/h | 0.0 mm | Moderate 19 |
| 6 Mar | 29.6 °C | 48 % | 21 km/h | 0.0 mm | Moderate 19 |
| 7 Mar | 32.1 °C | 41 % | 18 km/h | 0.0 mm | Moderate 19 |
| 8 Mar | 33.5 °C | 39 % | 18 km/h | 0.0 mm | Moderate 20 |
| 9 Mar | 31.4 °C | 48 % | 27 km/h | 0.0 mm | High 22 |
| 10 Mar | 31.7 °C | 47 % | 17 km/h | 0.0 mm | Moderate 20 |
| 11 Mar | 32.9 °C | 46 % | 18 km/h | 0.0 mm | Moderate 20 |
| 12 Mar | 32.0 °C | 51 % | 28 km/h | 0.0 mm | High 22 |
| 13 Mar after | 26.5 °C | 59 % | 40 km/h | 0.0 mm | Moderate 20 |
| 14 Mar after | 30.8 °C | 41 % | 18 km/h | 0.0 mm | Moderate 19 |
| 15 Mar after | 32.9 °C | 42 % | 19 km/h | 0.0 mm | Moderate 20 |
| 16 Mar after | 32.6 °C | 40 % | 19 km/h | 0.2 mm | Moderate 21 |
| 17 Mar after | 33.6 °C | 41 % | 23 km/h | 0.0 mm | Moderate 21 |
| 18 Mar after | 34.0 °C | 45 % | 23 km/h | 0.1 mm | High 22 |
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.
The smoke
CAMS · CopernicusOn 11 March 2023 the air beside the fire reached 61 µg/m³ of PM2.5. That day averaged 46: 3.0 times the WHO daily guideline (15).
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 · 43Every satellite heat detection, one by one, with time, satellite, power and coordinates.
| Date and time | Satellite | FRP (MW) | Lat | Lon |
|---|
Other fires nearby
- 4,640 haDan Sai ด่านซ้าย5 March 2019 · 19 days · 1 km away
- 6,404 haDan Sai ด่านซ้ายMarch 2016 · 19 days · 2 km away
- 7,219 haLom Kao หล่มเก่า8 April 2026 · 14 days · 26 km away
- 7,064 haLom Kao หล่มเก่าFebruary 2021 · 10 days · 30 km away
- 6,306 haPhu Ruea ภูเรือ27 March 2026 · 22 days · 33 km away
- 5,317 haNa Haeo นาแห้ว20 March 2023 · 19 days · 34 km away
Frequently asked questions
- How long did the Dan Sai fire last?
- According to the heat detections seen by satellite inside the perimeter, it burned from 25 February 2023 to 12 March 2023 (16 days). The perimeter dates it from 2 March 2023 to 8 March 2023.
- How much area did it burn?
- The perimeter GWIS (Copernicus) rebuilt from heat detections is 1,466 hectares (14.7 km²). It is an estimate: official national figures may differ.
- Which municipalities burned?
- The fire only entered Dan Sai (1,474 ha, 1.1 %).
- What was the weather like?
- During the fire the temperature reached 33.5 °C, humidity dropped to 34 % and gusts hit 30 km/h. The fire danger index (FWI) reached 22, 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: 8 March 2023 → 12 March 2023.
- Start date: 2 March 2023 → 25 February 2023.
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 2 March 2023 to 8 March 2023. 43 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.
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.