How long did the Thoen fire last?

GWIS (Copernicus) dates it between 22 February 2019 and 4 March 2019: 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 2,120 hectares (21.2 km²). It is an estimate: official national figures may differ.

Which municipalities burned?

The fire entered 2 municipalities: Mae Phrik (1,766 ha, 2.6 %); Thoen (367 ha, 0.2 %).

What was the weather like?

During the fire the temperature reached 36.7 °C, humidity dropped to 22 % and gusts hit 48 km/h. The fire danger index (FWI) reached 38, 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 · 2019-02-22 → 2019-03-04

Thoen fire, 22 February 2019 เถิน · Mae Phrik, Thoen

Out · last detection 4 Mar 2019, 19:07 UTC

The fire started on 22 February 2019 in Thoen, Thailand, and satellites saw it burning for 11 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 2,120 hectares from heat detections, spread across 2 municipalities.

It is the 58th largest in Lampang Province since 2016 (of 216 with a page). Number 103 in Thailand in 2019, of 385.

The power measured by the satellite is low (8.7 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: Thoen · 2017 Mae Phrik · 2017 Mae Phrik · 2026 Mae Phrik · 2024

Burnt area: 2,120ha; GWIS perimeter (Copernicus)
Duration: 11days; 22 Feb 2019 – 4 Mar 2019
Municipalities hit: 2; districts
Started on: 22 Feb; 2019
Heat detections: 77; in a single hotspot: 9 MW
Danger at start: 25; High · FWI index
Average daily power: 14MW; detected power per day, on average

HOTSPOTS BY DAY 22 Feb4 Mar

Play back 4 Mar 2019

How it evolved, day by day

22 Feb 24 Feb 26 Feb 28 Feb 3 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

37°high

48km/h · peak gust

22%lowest humidity

It had gone 4 days without rain (1 mm or more) when it started.

This area had burned before

73% of the perimeter overlaps earlier fires recorded since 2016: 271 ha in 2016, 1,254 ha in 2017, 378 ha in 2018. Part of it burned more than once, so the yearly figures add up to more than the 1,546 ha that had burned before.

How big is it?

It burned the equivalent of 1.3% of the area of London (21 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

Mae Phrik แม่พริก

1,766 ha

2.6 %
Thoen เถิน where it started

367 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 2020

Built-up area< 0.1 ha

Residents< 20

Inside the perimeter there was no noticeable built-up land and almost nobody lived there (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)
17 Feb	32.9 °C	34 %	48 km/h	0.2 mm	High 25
18 Feb	32.9 °C	33 %	39 km/h	0.0 mm	High 26
19 Feb	34.2 °C	28 %	27 km/h	0.0 mm	High 26
20 Feb	35.3 °C	24 %	25 km/h	0.0 mm	High 28
21 Feb	35.8 °C	25 %	21 km/h	0.0 mm	High 28
22 Feb	36.2 °C	22 %	27 km/h	0.0 mm	High 32
23 Feb	36.6 °C	26 %	23 km/h	0.0 mm	High 32
24 Feb	36.7 °C	22 %	19 km/h	0.0 mm	High 34
25 Feb	36.4 °C	23 %	26 km/h	0.0 mm	High 33
26 Feb	36.3 °C	27 %	20 km/h	0.0 mm	High 33
27 Feb	35.8 °C	30 %	17 km/h	0.0 mm	High 32
28 Feb	35.6 °C	33 %	22 km/h	0.0 mm	High 31
1 Mar	36.4 °C	27 %	24 km/h	0.0 mm	High 32
2 Mar	36.3 °C	26 %	29 km/h	0.0 mm	High 33
3 Mar	36.0 °C	26 %	27 km/h	0.0 mm	High 33
4 Mar	35.2 °C	26 %	39 km/h	0.0 mm	High 38
5 Mar after	35.2 °C	29 %	41 km/h	0.0 mm	Very high 39
6 Mar after	36.4 °C	26 %	32 km/h	0.0 mm	High 36
7 Mar after	35.7 °C	32 %	32 km/h	0.0 mm	High 36
8 Mar after	35.7 °C	30 %	42 km/h	0.0 mm	Very high 40
9 Mar after	35.4 °C	30 %	43 km/h	0.0 mm	Very high 40
10 Mar after	35.3 °C	25 %	34 km/h	0.0 mm	Very high 38
11 Mar after	36.2 °C	20 %	18 km/h	0.0 mm	High 37
12 Mar after	36.4 °C	26 %	21 km/h	0.0 mm	High 38
13 Mar after	36.6 °C	26 %	20 km/h	0.0 mm	High 38
14 Mar after	36.7 °C	30 %	22 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 · 15 Feb 2019

After · 11 Mar 2019

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 · 77Every 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 Thoen fire last?: GWIS (Copernicus) dates it between 22 February 2019 and 4 March 2019: 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 2,120 hectares (21.2 km²). It is an estimate: official national figures may differ.
Which municipalities burned?: The fire entered 2 municipalities: Mae Phrik (1,766 ha, 2.6 %); Thoen (367 ha, 0.2 %).
What was the weather like?: During the fire the temperature reached 36.7 °C, humidity dropped to 22 % and gusts hit 48 km/h. The fire danger index (FWI) reached 38, 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 · Emergency number and official warnings ›

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

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.

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What really happened?

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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. 77 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