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Long fire, March 2026 Long, Mae Mo

Out · last detection 30 Mar 2026, 18:42 UTC

The fire started on 27 March 2026 in Long, Thailand, and satellites saw it burning for 6 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 1,223 hectares from heat detections, spread across 2 municipalities.

It is the 75th largest in Phrae Province since 2016 (of 120 with a page). Number 669 in Thailand in 2026, of 880.

The power measured by the satellite is low (14.6 MW in the strongest hotspot), more typical of grass or stubble burning, or a slow surface fire, than of a large crown fire.

Burnt area
1,223ha
GWIS perimeter (Copernicus)
Duration
6days
27 Mar 2026 – 1 Apr 2026
Municipalities hit
2
districts
Started on
27 Mar
2026
Heat detections
22
in a single hotspot: 15 MW
Danger at start
31
High · FWI index
Energy released
74MW
sum of detected power

Where it burned

30 Mar 2026
HOTSPOTS BY DAY 27 Mar1 Apr

How it evolved, day by day

27282930

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

The weather it burned in

37°high
34km/h · peak gust
23%lowest humidity

It had gone 9 days without rain (1 mm or more) when it started.

This area had burned before

94% of the perimeter overlaps earlier fires recorded since 2016: 262 ha in 2016, 356 ha in 2017, 335 ha in 2019, 927 ha in 2020, 259 ha in 2021, 600 ha in 2025. Part of it burned more than once, so the yearly figures add up to more than the 1,151 ha that had burned before.

What happened to each town

  1. Long where it started
    1,067 ha reached on 27 Mar
    0.8 %
  2. Mae Mo
    164 ha reached on 27 Mar
    0.2 %

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)
23 Mar 35.8 °C 23 % 29 km/h 0.0 mm High 31
24 Mar 36.0 °C 23 % 27 km/h 0.0 mm High 31
25 Mar 36.4 °C 27 % 30 km/h 0.0 mm High 32
26 Mar 36.7 °C 25 % 26 km/h 0.0 mm High 32
27 Mar 36.9 °C 24 % 31 km/h 0.0 mm High 34
28 Mar 36.5 °C 29 % 31 km/h 0.0 mm High 36
29 Mar 36.1 °C 32 % 34 km/h 0.0 mm High 35
30 Mar 36.2 °C 28 % 29 km/h 0.0 mm High 34
31 Mar 36.2 °C 30 % 27 km/h 0.0 mm High 33
1 Apr 36.5 °C 32 % 23 km/h 0.0 mm High 33
2 Apr after 37.0 °C 30 % 28 km/h 0.0 mm High 34
3 Apr after 36.5 °C 31 % 26 km/h 0.0 mm High 34
4 Apr after 35.4 °C 36 % 24 km/h 0.0 mm High 32
5 Apr after 36.1 °C 36 % 27 km/h 0.0 mm High 33
6 Apr after 36.7 °C 33 % 26 km/h 0.0 mm High 33
7 Apr after 36.6 °C 36 % 27 km/h 0.0 mm High 34
8 Apr after 37.5 °C 26 % 30 km/h 0.0 mm High 36
9 Apr after 36.7 °C 25 % 29 km/h 0.0 mm High 37
10 Apr after 37.1 °C 26 % 30 km/h 0.0 mm High 37
11 Apr after 36.2 °C 30 % 34 km/h 0.0 mm Very high 38

Before and after, from space

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

Before · 20 Mar 2026
After · 8 Apr 2026

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 3 April 2026 the air beside the fire reached 80 µg/m³ of PM2.5. That day averaged 58: 3.9 times the WHO daily guideline (15).

PM2.5 peak80 µg/m³
Days over the guideline11 days
PM1092 µg/m³
Optical depth1.46
252627282930311234
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 · 22Every 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 timeSatelliteFRP (MW)LatLon

Other fires nearby

All fires in Thailand ›

Frequently asked questions

How long did the Long fire last?
GWIS (Copernicus) dates it between 27 March 2026 and 1 April 2026: 6 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 1,223 hectares (12.2 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire entered 2 municipalities: Long (1,067 ha, 0.8 %); Mae Mo (164 ha, 0.2 %).
What was the weather like?
During the fire the temperature reached 36.9 °C, humidity dropped to 23 % and gusts hit 34 km/h. The fire danger index (FWI) reached 36, class High.
Where does this data come from?
From the GWIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of Thailand (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.

Emergency number: 199 · 191

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
What do you think is wrong?

We will only use your email to reply about this report. Privacy. This is not an emergency service: if there is a fire now, call 199 · 191.

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.