How long did the Bualapha fire last?

According to the heat detections seen by satellite inside the perimeter, it burned from 10 March 2021 to 26 March 2021 (17 days). The perimeter dates it from 11 March 2021 to 19 March 2021.

How much area did it burn?

The perimeter GWIS (Copernicus) rebuilt from heat detections is 4,981 hectares (49.8 km²). It is an estimate: official national figures may differ.

Which municipalities burned?

The fire entered 2 municipalities: Bualapha (2,769 ha, 0.8 %); Vilabuly (2,237 ha, 1.3 %).

What was the weather like?

During the fire the temperature reached 37.6 °C, humidity dropped to 25 % and gusts hit 73 km/h. The fire danger index (FWI) reached 29, 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.

LA · Laos · 2021-03-10 → 2021-03-26

Bualapha fire, March 2021 Bualapha, Vilabuly

Out · last detection 26 Mar 2021, 18:47 UTC

The fire started on 10 March 2021 in Bualapha, Laos, and satellites saw it burning for 17 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 4,981 hectares from heat detections, spread across 2 municipalities.

It is the 7th largest in Khammouane since 2016 (of 54 with a page). Number 11 in Laos in 2021, of 88.

Compare with…

Suggestions: Bualapha · 2020 Bualapha · 2016 Vilabuly · 2021 Vilabuly · 2022

Burnt area: 4,981ha; GWIS perimeter (Copernicus)
Duration: 17days; 10 Mar 2021 – 26 Mar 2021
Municipalities hit: 2; districts
Started on: 10 Mar; 2021
Heat detections: 213; in a single hotspot: 329 MW
Danger at start: 18; Moderate · FWI index
Average daily power: 297MW; detected power per day, on average

HOTSPOTS BY DAY 10 Mar26 Mar

Play back 26 Mar 2021

How it evolved, day by day

10 Mar 13 Mar 16 Mar 17 Mar 19 Mar 23 Mar 26 Mar

Fire radiative power detected each day, in megawatts, and number of hotspots. The magenta bar marks the peak day.

The weather it burned in

38°high

73km/h · peak gust

25%lowest humidity

It had gone 5 days without rain (1 mm or more) when it started. Rain came after the fire: 2.0 mm on 1 Apr.

This area had burned before

37% of the perimeter overlaps earlier fires recorded since 2016: 395 ha in 2016, 659 ha in 2019, 1,249 ha in 2020. Part of it burned more than once, so the yearly figures add up to more than the 1,826 ha that had burned before.

How big is it?

It burned the equivalent of 3.1% of the area of London (50 km² against 1,583 km²).

London boundary: geoBoundaries · Office for National Statistics (Open Government Licence v3.0).

This compares size, not location: both shapes are at the same scale, north up, centred on each other.

What happened to each town

Bualapha where it started

2,769 ha reached on 10 Mar

0.8 %
Vilabuly

2,237 ha reached on 10 Mar

1.3 %

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.

People and buildings inside the perimeter

GHSL 2020

Built-up area2.7 ha

Residents≈ 950

Inside the perimeter there were about 2.7 hectares of built-up land and about 950 residents (GHSL 2020, satellite-based estimate).

This is an estimate on 100 m cells, made from satellite imagery and census data: it does not mean that homes burned or that anyone was harmed. The perimeter also contains land that never burned.

Source: Global Human Settlement Layer (GHS-BUILT-S and GHS-POP R2023A), European Commission Joint Research Centre (JRC), © European Union, CC BY 4.0. Sum inside the perimeter computed by WorldFires. human-settlement.emergency.copernicus.eu

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)
10 Mar	32.4 °C	41 %	31 km/h	0.0 mm	Moderate 18
11 Mar	33.0 °C	38 %	35 km/h	0.0 mm	Moderate 20
12 Mar	31.6 °C	42 %	42 km/h	0.0 mm	Moderate 21
13 Mar	31.5 °C	42 %	37 km/h	0.0 mm	Moderate 21
14 Mar	31.4 °C	41 %	37 km/h	0.0 mm	High 23
15 Mar	35.3 °C	31 %	23 km/h	0.0 mm	High 22
16 Mar	35.3 °C	34 %	25 km/h	0.0 mm	High 25
17 Mar	34.7 °C	36 %	18 km/h	0.0 mm	High 24
18 Mar	37.6 °C	25 %	24 km/h	0.0 mm	High 29
19 Mar	36.3 °C	38 %	26 km/h	0.0 mm	High 26
20 Mar	36.1 °C	40 %	27 km/h	2.8 mm	Low 10
21 Mar	31.2 °C	60 %	51 km/h	7.3 mm	Very low 4
22 Mar	22.2 °C	60 %	73 km/h	0.0 mm	Low 10
23 Mar	26.3 °C	47 %	52 km/h	0.0 mm	Moderate 13
24 Mar	27.8 °C	54 %	48 km/h	0.0 mm	Moderate 14
25 Mar	32.7 °C	41 %	35 km/h	0.2 mm	Moderate 17
26 Mar	35.2 °C	38 %	24 km/h	0.0 mm	Moderate 19
27 Mar after	35.6 °C	36 %	27 km/h	0.2 mm	Moderate 19
28 Mar after	35.1 °C	40 %	35 km/h	0.1 mm	Moderate 21
29 Mar after	36.7 °C	34 %	38 km/h	0.1 mm	High 23
30 Mar after	36.0 °C	38 %	45 km/h	0.0 mm	High 26
31 Mar after	36.7 °C	39 %	43 km/h	0.0 mm	High 25
1 Apr after	36.4 °C	41 %	37 km/h	2.0 mm	Moderate 14

Before and after, from space

Drag the line to compare the same ground before the fire and after it.

↔

Before · 3 Mar 2021

After · 2 Apr 2021

Before After

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.

⬇ Download CSV Times in UTC. Each detection is a 375 m pixel: a large fire yields hundreds per pass.

Date and time	Satellite	FRP (MW)	Lat	Lon

Other fires nearby

All fires in Laos ›

Frequently asked questions

How long did the Bualapha fire last?: According to the heat detections seen by satellite inside the perimeter, it burned from 10 March 2021 to 26 March 2021 (17 days). The perimeter dates it from 11 March 2021 to 19 March 2021.
How much area did it burn?: The perimeter GWIS (Copernicus) rebuilt from heat detections is 4,981 hectares (49.8 km²). It is an estimate: official national figures may differ.
Which municipalities burned?: The fire entered 2 municipalities: Bualapha (2,769 ha, 0.8 %); Vilabuly (2,237 ha, 1.3 %).
What was the weather like?: During the fire the temperature reached 37.6 °C, humidity dropped to 25 % and gusts hit 73 km/h. The fire danger index (FWI) reached 29, 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

NASA FIRMS ↗
GWIS · Copernicus ↗

History of this page Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.

No changes since 24 October 2026.

RSS Changes to this page

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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.

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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 11 March 2021 to 19 March 2021. 213 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.
Built-up area and population come from the JRC Global Human Settlement Layer (epoch 2020, 100 m cells), summed inside the perimeter: an estimate of what was there, not a damage count.

How we build fire pages: methodology ›

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.

Where it burned