How long did the May fire last?

GWIS (Copernicus) dates it between 10 April 2026 and 17 April 2026: 8 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 2,578 hectares (25.8 km²). It is an estimate: official national figures may differ.

Which municipalities burned?

The fire only entered May (2,589 ha, 0.9 %).

What was the weather like?

During the fire the temperature reached 32.5 °C, humidity dropped to 26 % and gusts hit 47 km/h. The fire danger index (FWI) reached 28, 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 · 2026-04-10 → 2026-04-17

May fire, 10 April 2026 May

Out · last detection 15 Apr 2026, 18:42 UTC

The fire started on 10 April 2026 in May, Laos, and satellites saw it burning for 8 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 2,578 hectares from heat detections, spread across a single municipality.

It is the 33th largest in Phongsaly since 2016 (of 63 with a page). Number 207 in Laos in 2026, of 308.

Compare with…

Suggestions: May · 2022 May · 2017 May · 2026 May · 2023

Burnt area: 2,578ha; GWIS perimeter (Copernicus)
Duration: 8days; 10 Apr 2026 – 17 Apr 2026
Municipalities hit: 1; districts
Started on: 10 Apr; 2026
Heat detections: 53; in a single hotspot: 54 MW
Danger at start: 23; High · FWI index
Average daily power: 113MW; detected power per day, on average

HOTSPOTS BY DAY 10 Apr17 Apr

Play back 15 Apr 2026

How it evolved, day by day

11 Apr 12 Apr 13 Apr 14 Apr 15 Apr

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

The weather it burned in

32°high

47km/h · peak gust

26%lowest humidity

It had gone one day without rain (1 mm or more) when it started. Rain came after the fire: 9.8 mm on 19 Apr.

This area had burned before

62% of the perimeter overlaps earlier fires recorded since 2016: 1,005 ha in 2019, 9 ha in 2022, 597 ha in 2023.

9 ha May fire, April 2022 2,491 ha in total; the hectares shown are those it shares with this fire

How big is it?

It burned the equivalent of 1.6% of the area of London (26 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

May where it started

2,589 ha

0.9 %

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)
10 Apr	29.5 °C	36 %	47 km/h	0.0 mm	High 23
11 Apr	30.0 °C	35 %	47 km/h	0.0 mm	High 24
12 Apr	31.2 °C	26 %	35 km/h	0.0 mm	High 26
13 Apr	32.5 °C	29 %	33 km/h	0.0 mm	High 26
14 Apr	30.9 °C	36 %	36 km/h	0.0 mm	High 26
15 Apr	30.9 °C	35 %	37 km/h	0.0 mm	High 28
16 Apr	31.0 °C	34 %	31 km/h	0.0 mm	High 26
17 Apr	31.2 °C	37 %	29 km/h	0.0 mm	High 26
18 Apr after	27.6 °C	48 %	31 km/h	0.1 mm	Moderate 21
19 Apr after	26.7 °C	60 %	38 km/h	9.8 mm	Very low 1

Before and after, from space

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

↔

Before · 3 Apr 2026

After · 24 Apr 2026

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.

The smoke

CAMS · Copernicus

On 18 April 2026 the air beside the fire reached 190 µg/m³ of PM2.5. That day averaged 125: 8.4 times the WHO daily guideline (15).

PM2.5 peak190 µg/m³

Days over the guideline13 days

PM10219 µg/m³

Optical depth3.24

WHO 15

891011121314151617181920

Good Fair Moderate Poor Very poor Extremely poor

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 · 53Every 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 May fire last?: GWIS (Copernicus) dates it between 10 April 2026 and 17 April 2026: 8 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 2,578 hectares (25.8 km²). It is an estimate: official national figures may differ.
Which municipalities burned?: The fire only entered May (2,589 ha, 0.9 %).
What was the weather like?: During the fire the temperature reached 32.5 °C, humidity dropped to 26 % and gusts hit 47 km/h. The fire danger index (FWI) reached 28, 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 ↗

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

What do you think is wrong?

Dates or duration Place or towns Burned area Name It was not a wildfire Same fire as another page Something else

What really happened?

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How we know this

Perimeter: GWIS (Copernicus), rebuilt from heat detections rather than mapped on imagery.
Dates from the perimeter: the VIIRS detections inside it did not change them. 53 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.

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