Phiang fire, March 2025 Phiang
The fire started on 23 March 2025 in Phiang, Laos, and satellites saw it burning for 9 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 8,044 hectares from heat detections, spread across a single municipality.
It is the 18th largest in Xaignabouli since 2016 (of 122 with a page). Number 2 in Laos in 2025, of 51.
- Burnt area
- 8,044ha
- GWIS perimeter (Copernicus)
- Duration
- 9days
- 23 Mar 2025 – 31 Mar 2025
- Municipalities hit
- 1
- districts
- Started on
- 23 Mar
- 2025
- Heat detections
- 350
- in a single hotspot: 31 MW
- Danger at start
- 19
- Moderate · FWI index
- Energy released
- 1.6GW
- sum of detected power
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 9 days without rain (1 mm or more) when it started. Rain came after the fire: 12.0 mm on 5 Apr.
This area had burned before
86% of the perimeter overlaps earlier fires recorded since 2016: 1,058 ha in 2016, 8 ha in 2017, 4,198 ha in 2019, 1,661 ha in 2020, 6,288 ha in 2023, 361 ha in 2024. Part of it burned more than once, so the yearly figures add up to more than the 6,924 ha that had burned before.
- 6,279 ha Phiang fire, March 2023 13,358 ha in total; the hectares shown are those it shares with this fire
- 1,058 ha Phiang fire, April 2016 18,466 ha in total; the hectares shown are those it shares with this fire
- 622 ha Phiang fire, March 2020 2,382 ha in total; the hectares shown are those it shares with this fire
- 611 ha Phiang fire, April 2019 3,106 ha in total; the hectares shown are those it shares with this fire
- 9 ha Mae Charim fire, March 2023 22,836 ha in total; the hectares shown are those it shares with this fire
- 8 ha Phiang fire, April 2017 3,175 ha in total; the hectares shown are those it shares with this fire
What happened to each town
-
Phiang where it started8,078 ha reached on 23 Mar2.9 %
Burnt area inside each municipality, from crossing the GWIS perimeter with administrative boundaries. The distance is from the town centre 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) |
|---|---|---|---|---|---|
| 23 Mar | 33.8 °C | 35 % | 22 km/h | 0.0 mm | Moderate 19 |
| 24 Mar | 35.5 °C | 32 % | 21 km/h | 0.0 mm | Moderate 21 |
| 25 Mar | 35.4 °C | 36 % | 26 km/h | 0.0 mm | High 22 |
| 26 Mar | 37.0 °C | 28 % | 30 km/h | 0.0 mm | High 26 |
| 27 Mar | 37.3 °C | 23 % | 31 km/h | 0.0 mm | High 30 |
| 28 Mar | 36.7 °C | 28 % | 31 km/h | 0.0 mm | High 30 |
| 29 Mar | 36.4 °C | 34 % | 32 km/h | 0.0 mm | High 29 |
| 30 Mar | 31.1 °C | 51 % | 39 km/h | 0.5 mm | High 23 |
| 31 Mar | 30.6 °C | 54 % | 34 km/h | 0.0 mm | Moderate 20 |
| 1 Apr after | 29.1 °C | 53 % | 35 km/h | 0.0 mm | Moderate 20 |
| 2 Apr after | 31.2 °C | 48 % | 26 km/h | 0.0 mm | Moderate 18 |
| 3 Apr after | 32.5 °C | 45 % | 26 km/h | 0.0 mm | Moderate 19 |
| 4 Apr after | 35.2 °C | 42 % | 26 km/h | 0.0 mm | Moderate 20 |
| 5 Apr after | 34.5 °C | 45 % | 31 km/h | 12.0 mm | Very low 3 |
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 29 March 2025 the air beside the fire reached 197 µg/m³ of PM2.5. That day averaged 106: 7.1 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 · 350Every satellite heat detection, one by one, with time, satellite, power and coordinates.
| Date and time | Satellite | FRP (MW) | Lat | Lon |
|---|
Other fires nearby
- 13,358 haPhiang15 March 2023 · 24 days · 3 km away
- 18,466 haPhiang3 April 2016 · 22 days · 6 km away
- 15,266 haBo Kluea23 March 2020 · 12 days · 21 km away
- 22,836 haMae Charim21 March 2023 · 21 days · 27 km away
- 44,232 haParklai14 March 2026 · 43 days · 28 km away
- 14,010 haParklai15 March 2023 · 36 days · 28 km away
Frequently asked questions
- How long did the Phiang fire last?
- According to the heat detections seen by satellite inside the perimeter, it burned from 23 March 2025 to 31 March 2025 (9 days). The perimeter dates it from 24 March 2025 to 29 March 2025.
- How much area did it burn?
- The perimeter GWIS (Copernicus) rebuilt from heat detections is 8,044 hectares (80.4 km²). It is an estimate: official national figures may differ.
- Which municipalities burned?
- The fire only entered Phiang (8,078 ha, 2.9 %).
- What was the weather like?
- During the fire the temperature reached 37.3 °C, humidity dropped to 23 % and gusts hit 39 km/h. The fire danger index (FWI) reached 30, class High.
- Where does this data come from?
- From the GWIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of Laos (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.
Satellite cross-check
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
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.