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Chun fire, 27 March 2026 จุน · Chun, Pong, Chiang Kham

Out · last detection 4 Apr 2026, 18:49 UTC

The fire started on 27 March 2026 in Chun, Thailand, and satellites saw it burning for 11 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 1,746 hectares from heat detections, spread across 3 municipalities.

It is the 45th largest in Phayao Province since 2016 (of 111 with a page). Number 359 in Thailand in 2026, of 689.

The power measured by the satellite is low (5.9 MW in the strongest hotspot), more typical of grass or stubble burning, or a slow surface fire, than of a large crown fire.

Compare with…

Suggestions: Chiang Kham · 2023Dok Khamtai · 2026Pong · 2026Chiang Kham · 2020

Burnt area
1,746ha
GWIS perimeter (Copernicus)
Duration
11days
27 Mar 2026 – 6 Apr 2026
Municipalities hit
3
districts
Started on
27 Mar
2026
Heat detections
20
in a single hotspot: 6 MW
Danger at start
29
High · FWI index
Average daily power
8MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 27 Mar6 Apr
4 Apr 2026

How it evolved, day by day

27 Mar 2026 · 7 MW · 2 29 Mar 2026 · 16 MW · 7 30 Mar 2026 · 9 MW · 6 2 Apr 2026 · 4 MW · 1 3 Apr 2026 · 5 MW · 3 4 Apr 2026 · 6 MW · 1
27 Mar 29 Mar 30 Mar 2 Apr 3 Apr 4 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

38°high
40km/h · peak gust
21%lowest humidity

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

This area had burned before

56% of the perimeter overlaps earlier fires recorded since 2016: 260 ha in 2019, 560 ha in 2020, 51 ha in 2021, 279 ha in 2023, 277 ha in 2025. Part of it burned more than once, so the yearly figures add up to more than the 972 ha that had burned before.

How big is it?

10 km
It burned the equivalent of 1.1% of the area of London (17 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

  1. Chun จุน where it started
    1,419 ha
    2.7 %
  2. Pong ปง
    200 ha
    0.1 %
  3. Chiang Kham เชียงคำ
    136 ha
    0.2 %

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 2025
Built-up area0.13 ha
Residents< 20

Inside the perimeter there were about 0.13 hectares of built-up land and almost nobody lived there (GHSL 2025, 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. The GHSL 2025 epoch is a projection made from 2020 and earlier data.

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)
23 Mar 36.7 °C 21 % 30 km/h 0.0 mm High 29
24 Mar 36.9 °C 22 % 24 km/h 0.0 mm High 28
25 Mar 37.0 °C 22 % 31 km/h 0.0 mm High 31
26 Mar 36.9 °C 22 % 28 km/h 0.0 mm High 31
27 Mar 37.5 °C 22 % 34 km/h 0.0 mm High 34
28 Mar 37.6 °C 25 % 32 km/h 0.0 mm High 34
29 Mar 37.4 °C 23 % 40 km/h 0.1 mm Very high 38
30 Mar 37.0 °C 26 % 30 km/h 0.0 mm High 35
31 Mar 37.2 °C 29 % 28 km/h 0.0 mm High 34
1 Apr 37.1 °C 33 % 22 km/h 0.0 mm High 30
2 Apr 37.8 °C 29 % 30 km/h 0.0 mm High 34
3 Apr 37.8 °C 30 % 26 km/h 0.0 mm High 32
4 Apr 36.6 °C 35 % 26 km/h 0.0 mm High 31
5 Apr 37.8 °C 34 % 28 km/h 0.0 mm High 32
6 Apr 37.5 °C 34 % 26 km/h 0.0 mm High 31
7 Apr after 37.3 °C 37 % 27 km/h 0.0 mm High 32
8 Apr after 38.0 °C 27 % 28 km/h 0.0 mm High 34
9 Apr after 37.5 °C 28 % 28 km/h 0.0 mm High 33
10 Apr after 38.0 °C 25 % 35 km/h 0.0 mm Very high 39
11 Apr after 37.2 °C 28 % 34 km/h 0.0 mm Very high 38
12 Apr after 37.7 °C 22 % 23 km/h 0.0 mm High 35
13 Apr after 37.9 °C 30 % 22 km/h 0.0 mm High 35
14 Apr after 38.6 °C 30 % 23 km/h 0.0 mm High 36
15 Apr after 39.1 °C 22 % 33 km/h 0.0 mm Very high 42
16 Apr after 38.2 °C 25 % 24 km/h 0.0 mm High 37

Before and after, from space

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

Before · 20 Mar 2026
After · 13 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 4 April 2026 the air beside the fire reached 119 µg/m³ of PM2.5. That day averaged 75: 5.0 times the WHO daily guideline (15).

PM2.5 peak119 µg/m³
Days over the guideline16 days
PM10147 µg/m³
Optical depth2.34
25262728293031123456789
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 · 20Every 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 Chun fire last?
GWIS (Copernicus) dates it between 27 March 2026 and 6 April 2026: 11 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 1,746 hectares (17.5 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire entered 3 municipalities: Chun (1,419 ha, 2.7 %); Pong (200 ha, 0.1 %); Chiang Kham (136 ha, 0.2 %).
What was the weather like?
During the fire the temperature reached 37.8 °C, humidity dropped to 21 % and gusts hit 40 km/h. The fire danger index (FWI) reached 38, class Very 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 · Emergency number and official warnings ›

Satellite cross-check

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

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.

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. 20 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 2025, 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.