Sepone fire, April 2025 Nong, Sepone
The fire started on 4 April 2025 in Sepone, Laos, and satellites saw it burning for 12 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 3,660 hectares from heat detections, spread across 2 municipalities.
It is the 27th largest in Savannakhet since 2016 (of 96 with a page). Number 14 in Laos in 2025, of 51.
- Burnt area
- 3,660ha
- GWIS perimeter (Copernicus)
- Duration
- 12days
- 4 Apr 2025 – 15 Apr 2025
- Municipalities hit
- 2
- districts
- Started on
- 4 Apr
- 2025
- Heat detections
- 112
- in a single hotspot: 199 MW
- Danger at start
- 15
- Moderate · FWI index
- Energy released
- 2.5GW
- 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 5 days without rain (1 mm or more) when it started. Rain came after the fire: 2.7 mm on 18 Apr.
This area had burned before
91% of the perimeter overlaps earlier fires recorded since 2016: 47 ha in 2016, 1,351 ha in 2017, 916 ha in 2018, 1,618 ha in 2019, 1,397 ha in 2020, 978 ha in 2021, 1,729 ha in 2022, 957 ha in 2023, 208 ha in 2024. Part of it burned more than once, so the yearly figures add up to more than the 3,338 ha that had burned before.
- 837 ha Nong fire, April 2017 12,875 ha in total; the hectares shown are those it shares with this fire
- 489 ha Nong fire, March 2023 2,582 ha in total; the hectares shown are those it shares with this fire
- 446 ha Nong fire, February 2019 8,879 ha in total; the hectares shown are those it shares with this fire
- 115 ha Nong fire, March 2019 2,839 ha in total; the hectares shown are those it shares with this fire
- 34 ha Nong fire, March 2021 2,071 ha in total; the hectares shown are those it shares with this fire
- 24 ha Nong fire, March 2020 2,587 ha in total; the hectares shown are those it shares with this fire
- 12 ha Nong fire, April 2022 6,823 ha in total; the hectares shown are those it shares with this fire
What happened to each town
-
3,212 ha reached on 5 Apr1.7 %
-
Sepone where it started469 ha reached on 4 Apr0.2 %
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) |
|---|---|---|---|---|---|
| 4 Apr | 31.4 °C | 51 % | 32 km/h | 0.0 mm | Moderate 15 |
| 5 Apr | 33.9 °C | 47 % | 41 km/h | 0.4 mm | Moderate 19 |
| 6 Apr | 30.2 °C | 60 % | 38 km/h | 0.2 mm | Moderate 17 |
| 7 Apr | 31.0 °C | 58 % | 37 km/h | 0.0 mm | Moderate 17 |
| 8 Apr | 33.1 °C | 53 % | 35 km/h | 0.3 mm | Moderate 17 |
| 9 Apr | 35.6 °C | 41 % | 25 km/h | 0.5 mm | Moderate 19 |
| 10 Apr | 32.3 °C | 56 % | 41 km/h | 11.4 mm | Very low 3 |
| 11 Apr | 34.8 °C | 44 % | 41 km/h | 0.0 mm | Moderate 13 |
| 12 Apr | 36.7 °C | 41 % | 48 km/h | 1.5 mm | Moderate 16 |
| 13 Apr | 25.8 °C | 67 % | 55 km/h | 9.4 mm | Very low 2 |
| 14 Apr | 28.0 °C | 56 % | 40 km/h | 0.0 mm | Very low 4 |
| 15 Apr | 32.2 °C | 39 % | 39 km/h | 0.0 mm | Moderate 14 |
| 16 Apr after | 35.3 °C | 37 % | 30 km/h | 0.0 mm | Moderate 16 |
| 17 Apr after | 34.3 °C | 48 % | 45 km/h | 0.6 mm | Moderate 16 |
| 18 Apr after | 36.6 °C | 39 % | 44 km/h | 2.7 mm | Low 11 |
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 10 April 2025 the air beside the fire reached 209 µg/m³ of PM2.5. That day averaged 138: 9.2 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 · 112Every satellite heat detection, one by one, with time, satellite, power and coordinates.
| Date and time | Satellite | FRP (MW) | Lat | Lon |
|---|
Other fires nearby
Frequently asked questions
- How long did the Sepone fire last?
- According to the heat detections seen by satellite inside the perimeter, it burned from 4 April 2025 to 15 April 2025 (12 days). The perimeter dates it from 4 April 2025 to 9 April 2025.
- How much area did it burn?
- The perimeter GWIS (Copernicus) rebuilt from heat detections is 3,660 hectares (36.6 km²). It is an estimate: official national figures may differ.
- Which municipalities burned?
- The fire entered 2 municipalities: Nong (3,212 ha, 1.7 %); Sepone (469 ha, 0.2 %).
- What was the weather like?
- During the fire the temperature reached 36.7 °C, humidity dropped to 39 % and gusts hit 55 km/h. The fire danger index (FWI) reached 19, class Moderate.
- 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.