Xay fire, 20 April 2021 Xay, Namor
The fire started on 20 April 2021 in Xay, Laos, and satellites saw it burning for 5 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 7,436 hectares from heat detections, spread across 2 municipalities.
It is the 32th largest in Oudomxay since 2016 (of 241 with a page). Number 3 in Laos in 2021, of 86.
- Burnt area
- 7,436ha
- GWIS perimeter (Copernicus)
- Duration
- 5days
- 20 Apr 2021 – 24 Apr 2021
- Municipalities hit
- 2
- districts
- Started on
- 20 Apr
- 2021
- Heat detections
- 213
- in a single hotspot: 518 MW
- Danger at start
- 6
- Low · FWI index
- Energy released
- 14.2GW
- 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 one day without rain (1 mm or more) when it started. Rain came after the fire: 2.9 mm on 25 Apr.
This area had burned before
94% of the perimeter overlaps earlier fires recorded since 2016: 5,415 ha in 2016, 3,359 ha in 2017, 2,156 ha in 2018, 5,526 ha in 2019, 4,340 ha in 2020. Part of it burned more than once, so the yearly figures add up to more than the 6,987 ha that had burned before.
- 4,537 ha Xay fire, April 2016 23,891 ha in total; the hectares shown are those it shares with this fire
- 3,359 ha Namor fire, April 2017 29,869 ha in total; the hectares shown are those it shares with this fire
- 3,033 ha Namor fire, March 2019 23,964 ha in total; the hectares shown are those it shares with this fire
- 2,156 ha Xay fire, April 2018 31,315 ha in total; the hectares shown are those it shares with this fire
- 1,980 ha Xay fire, April 2020 4,092 ha in total; the hectares shown are those it shares with this fire
- 1,317 ha Xay fire, April 2019 2,809 ha in total; the hectares shown are those it shares with this fire
- 1,246 ha Namor fire, April 2020 3,468 ha in total; the hectares shown are those it shares with this fire
- 191 ha Xay fire, April 2020 3,975 ha in total; the hectares shown are those it shares with this fire
What happened to each town
-
Xay where it started4,505 ha reached on 20 Apr2.1 %
-
2,962 ha reached on 21 Apr1.7 %
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) |
|---|---|---|---|---|---|
| 20 Apr | 31.9 °C | 44 % | 37 km/h | 0.6 mm | Low 6 |
| 21 Apr | 33.1 °C | 38 % | 33 km/h | 0.0 mm | Low 10 |
| 22 Apr | 35.7 °C | 30 % | 33 km/h | 0.0 mm | Moderate 15 |
| 23 Apr | 36.0 °C | 31 % | 36 km/h | 0.0 mm | Moderate 16 |
| 24 Apr | 35.6 °C | 38 % | 34 km/h | 0.0 mm | Moderate 17 |
| 25 Apr after | 32.8 °C | 53 % | 38 km/h | 2.9 mm | Very low 4 |
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 · 213Every 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?
- GWIS (Copernicus) dates it between 20 April 2021 and 24 April 2021: 5 days between the first and last heat detection of the perimeter.
- How much area did it burn?
- The perimeter GWIS (Copernicus) rebuilt from heat detections is 7,436 hectares (74.4 km²). It is an estimate: official national figures may differ.
- Which municipalities burned?
- The fire entered 2 municipalities: Xay (4,505 ha, 2.1 %); Namor (2,962 ha, 1.7 %).
- What was the weather like?
- During the fire the temperature reached 36.0 °C, humidity dropped to 30 % and gusts hit 37 km/h. The fire danger index (FWI) reached 17, 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.