Xay fire, 19 March 2023 Namor, Xay, Nalae
The fire started on 19 March 2023 in Xay, Laos, and satellites saw it burning for 39 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 60,413 hectares from heat detections, spread across 3 municipalities.
It is the largest fire in Oudomxay since 2016 (of 241 with a page). The largest in Laos in 2023, of 214.
- Burnt area
- 60,413ha
- GWIS perimeter (Copernicus)
- Duration
- 39days
- 19 Mar 2023 – 26 Apr 2023
- Municipalities hit
- 3
- districts
- Started on
- 19 Mar
- 2023
- Heat detections
- 3,142
- in a single hotspot: 601 MW
- Danger at start
- 25
- High · FWI index
- Energy released
- 122.4GW
- 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 more than two months without rain (1 mm or more) when it started. Rain came after the fire: 18.4 mm on 30 Apr.
This area had burned before
95% of the perimeter overlaps earlier fires recorded since 2016: 32,468 ha in 2016, 27,679 ha in 2017, 23,282 ha in 2018, 32,320 ha in 2019, 19,179 ha in 2020, 22,022 ha in 2021, 32,245 ha in 2022. Part of it burned more than once, so the yearly figures add up to more than the 57,399 ha that had burned before.
- 19,628 ha Namor fire, April 2017 29,869 ha in total; the hectares shown are those it shares with this fire
- 18,893 ha Namor fire, March 2019 23,964 ha in total; the hectares shown are those it shares with this fire
- 18,678 ha Xay fire, April 2016 23,891 ha in total; the hectares shown are those it shares with this fire
- 18,163 ha Xay fire, April 2018 31,315 ha in total; the hectares shown are those it shares with this fire
- 5,851 ha Xay fire, April 2021 7,436 ha in total; the hectares shown are those it shares with this fire
- 5,668 ha Namor fire, April 2022 6,722 ha in total; the hectares shown are those it shares with this fire
- 5,124 ha Namor fire, April 2022 7,204 ha in total; the hectares shown are those it shares with this fire
- 4,635 ha Xay fire, April 2022 5,457 ha in total; the hectares shown are those it shares with this fire
What happened to each town
-
40,715 ha reached on 22 Mar23 %
-
Xay where it started19,535 ha reached on 19 Mar9.1 %
-
421 ha reached on 10 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) |
|---|---|---|---|---|---|
| 19 Mar | 31.6 °C | 36 % | 38 km/h | 0.2 mm | High 25 |
| 20 Mar | 31.6 °C | 34 % | 46 km/h | 0.0 mm | High 27 |
| 21 Mar | 31.4 °C | 32 % | 49 km/h | 0.0 mm | High 31 |
| 22 Mar | 32.2 °C | 26 % | 51 km/h | 0.0 mm | High 36 |
| 23 Mar | 32.2 °C | 24 % | 49 km/h | 0.2 mm | High 37 |
| 24 Mar | 32.3 °C | 26 % | 40 km/h | 0.0 mm | High 34 |
| 25 Mar | 32.1 °C | 31 % | 36 km/h | 0.0 mm | High 33 |
| 26 Mar | 32.1 °C | 26 % | 44 km/h | 0.0 mm | High 37 |
| 27 Mar | 31.6 °C | 32 % | 32 km/h | 0.0 mm | High 32 |
| 28 Mar | 31.3 °C | 33 % | 40 km/h | 0.0 mm | High 34 |
| 29 Mar | 30.7 °C | 34 % | 35 km/h | 2.1 mm | Moderate 13 |
| 30 Mar | 30.7 °C | 35 % | 37 km/h | 0.1 mm | High 24 |
| 31 Mar | 31.8 °C | 31 % | 38 km/h | 0.0 mm | High 27 |
| 1 Apr | 32.9 °C | 30 % | 40 km/h | 0.0 mm | High 30 |
| 2 Apr | 32.0 °C | 31 % | 48 km/h | 0.0 mm | High 34 |
| 3 Apr | 31.4 °C | 30 % | 47 km/h | 0.0 mm | High 33 |
| 4 Apr | 32.3 °C | 26 % | 48 km/h | 0.0 mm | High 36 |
| 5 Apr | 33.0 °C | 21 % | 37 km/h | 0.0 mm | High 36 |
| 6 Apr | 33.1 °C | 28 % | 28 km/h | 0.0 mm | High 33 |
| 7 Apr | 32.7 °C | 31 % | 38 km/h | 0.0 mm | High 36 |
| 8 Apr | 31.5 °C | 41 % | 30 km/h | 0.1 mm | High 29 |
| 9 Apr | 32.1 °C | 42 % | 35 km/h | 0.4 mm | High 29 |
| 10 Apr | 34.7 °C | 27 % | 37 km/h | 0.0 mm | High 35 |
| 11 Apr | 35.2 °C | 27 % | 33 km/h | 0.0 mm | High 34 |
| 12 Apr | 35.0 °C | 25 % | 35 km/h | 0.0 mm | High 36 |
| 13 Apr | 34.7 °C | 31 % | 38 km/h | 0.0 mm | High 38 |
| 14 Apr | 35.6 °C | 28 % | 35 km/h | 0.0 mm | High 37 |
| 15 Apr | 35.1 °C | 27 % | 32 km/h | 0.0 mm | High 38 |
| 16 Apr | 33.9 °C | 39 % | 38 km/h | 0.0 mm | High 34 |
| 17 Apr | 34.2 °C | 33 % | 42 km/h | 0.0 mm | High 36 |
| 18 Apr | 36.4 °C | 26 % | 44 km/h | 0.0 mm | Very high 41 |
| 19 Apr | 36.6 °C | 23 % | 43 km/h | 0.0 mm | Very high 42 |
| 20 Apr | 36.4 °C | 22 % | 41 km/h | 0.0 mm | Very high 43 |
| 21 Apr | 36.1 °C | 24 % | 42 km/h | 0.0 mm | Very high 43 |
| 22 Apr | 34.3 °C | 33 % | 43 km/h | 0.6 mm | High 34 |
| 23 Apr | 35.9 °C | 23 % | 38 km/h | 0.0 mm | Very high 39 |
| 24 Apr | 33.1 °C | 32 % | 38 km/h | 0.0 mm | High 36 |
| 25 Apr | 34.6 °C | 31 % | 31 km/h | 0.0 mm | High 36 |
| 26 Apr | 30.5 °C | 50 % | 36 km/h | 4.1 mm | Low 6 |
| 27 Apr after | 31.9 °C | 41 % | 41 km/h | 0.0 mm | Moderate 18 |
| 28 Apr after | 33.7 °C | 34 % | 35 km/h | 0.0 mm | High 25 |
| 29 Apr after | 34.6 °C | 32 % | 38 km/h | 0.8 mm | High 31 |
| 30 Apr after | 26.5 °C | 68 % | 29 km/h | 18.4 mm | Very low 0 |
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 · 3,142Every 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 Xay fire last?
- According to the heat detections seen by satellite inside the perimeter, it burned from 19 March 2023 to 26 April 2023 (39 days). The perimeter dates it from 22 March 2023 to 24 April 2023.
- How much area did it burn?
- The perimeter GWIS (Copernicus) rebuilt from heat detections is 60,413 hectares (604.1 km²). It is an estimate: official national figures may differ.
- Which municipalities burned?
- The fire entered 3 municipalities: Namor (40,715 ha, 23 %); Xay (19,535 ha, 9.1 %); Nalae (421 ha, 0.2 %).
- What was the weather like?
- During the fire the temperature reached 36.6 °C, humidity dropped to 21 % and gusts hit 51 km/h. The fire danger index (FWI) reached 43, class Very 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.