How long did the Pong fire last?

GWIS (Copernicus) dates it between 25 March 2025 and 1 April 2025: 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 3,390 hectares (33.9 km²). It is an estimate: official national figures may differ.

Which municipalities burned?

The fire only entered Pong (3,406 ha, 2.0 %).

What was the weather like?

During the fire the temperature reached 37.9 °C, humidity dropped to 20 % and gusts hit 41 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.

TH · Thailand · 2025-03-25 → 2025-04-01

Pong fire, March 2025 Pong

Out · last detection 1 Apr 2025, 18:42 UTC

The fire started on 25 March 2025 in Pong, Thailand, and satellites saw it burning for 8 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 3,390 hectares from heat detections, spread across a single municipality.

It is the 20th largest in Phayao Province since 2016 (of 125 with a page). Number 19 in Thailand in 2025, of 239.

The power measured by the satellite is low (13.2 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: 3,390ha; GWIS perimeter (Copernicus)
Duration: 8days; 25 Mar 2025 – 1 Apr 2025
Municipalities hit: 1; districts
Started on: 25 Mar; 2025
Heat detections: 116; in a single hotspot: 13 MW
Danger at start: 7; Low · FWI index
Energy released: 331MW; sum of detected power

Play back 1 Apr 2025

HOTSPOTS BY DAY 25 Mar1 Apr

How it evolved, day by day

252627282930311

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

41km/h · peak gust

20%lowest humidity

It had gone 0 days without rain (1 mm or more) when it started. Rain came after the fire: 4.7 mm on 5 Apr.

This area had burned before

80% of the perimeter overlaps earlier fires recorded since 2016: 1,216 ha in 2016, 530 ha in 2017, 297 ha in 2018, 1,970 ha in 2019, 885 ha in 2020, 158 ha in 2022, 1,351 ha in 2023, 266 ha in 2024. Part of it burned more than once, so the yearly figures add up to more than the 2,698 ha that had burned before.

What happened to each town

Pong where it started

3,406 ha reached on 20 Mar

2.0 %

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 Mar	27.4 °C	46 %	20 km/h	0.0 mm	Low 7
21 Mar	30.1 °C	40 %	22 km/h	0.0 mm	Moderate 15
22 Mar	32.7 °C	35 %	23 km/h	0.0 mm	Moderate 20
23 Mar	34.6 °C	35 %	23 km/h	0.0 mm	High 22
24 Mar	36.3 °C	28 %	22 km/h	0.0 mm	High 25
25 Mar	36.3 °C	29 %	27 km/h	0.0 mm	High 28
26 Mar	37.2 °C	21 %	34 km/h	0.0 mm	High 35
27 Mar	37.0 °C	20 %	32 km/h	0.0 mm	High 36
28 Mar	36.8 °C	24 %	27 km/h	0.0 mm	High 36
29 Mar	37.9 °C	22 %	30 km/h	0.0 mm	High 34
30 Mar	35.2 °C	40 %	41 km/h	0.1 mm	High 34
31 Mar	33.7 °C	44 %	34 km/h	0.2 mm	High 28
1 Apr	32.9 °C	43 %	37 km/h	2.1 mm	Moderate 13
2 Apr after	33.2 °C	41 %	30 km/h	0.0 mm	High 22
3 Apr after	34.8 °C	38 %	30 km/h	0.0 mm	High 25
4 Apr after	35.8 °C	40 %	34 km/h	0.1 mm	High 25
5 Apr after	33.8 °C	44 %	35 km/h	4.7 mm	Low 7

Before and after, from space

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

↔

Before · 18 Mar 2025

After · 8 Apr 2025

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 24 March 2025 the air beside the fire reached 107 µg/m³ of PM2.5. That day averaged 80: 5.4 times the WHO daily guideline (15).

PM2.5 peak107 µg/m³

Days over the guideline13 days

PM10111 µg/m³

Optical depth1.68

WHO 15

2324252627282930311234

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 · 116Every 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 Thailand ›

Frequently asked questions

How long did the Pong fire last?: GWIS (Copernicus) dates it between 25 March 2025 and 1 April 2025: 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 3,390 hectares (33.9 km²). It is an estimate: official national figures may differ.
Which municipalities burned?: The fire only entered Pong (3,406 ha, 2.0 %).
What was the weather like?: During the fire the temperature reached 37.9 °C, humidity dropped to 20 % and gusts hit 41 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

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?

Your connection to the fire (optional) Email (optional)

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.

Where it burned