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TH · Thailand · –

Pang Mapha fire, February 2021 ปางมะผ้า · Pang Mapha, Pai

Out · last detection 11 Mar 2021, 18:28 UTC

The fire started on 23 February 2021 in Pang Mapha, Thailand, and satellites saw it burning for 17 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 1,035 hectares from heat detections, spread across 2 municipalities.

It is the 341th largest in Mae Hong Son Province since 2016 (of 361 with a page). Number 172 in Thailand in 2021, of 187.

Burnt area
1,035ha
GWIS perimeter (Copernicus)
Duration
17days
23 Feb 2021 – 11 Mar 2021
Municipalities hit
2
districts
Started on
23 Feb
2021
Heat detections
28
in a single hotspot: 66 MW
Danger at start
18
Moderate · FWI index
Average daily power
31MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 23 Feb11 Mar
11 Mar 2021

How it evolved, day by day

26 Feb 2021 · 51 MW · 1 27 Feb 2021 · 1 MW · 1 1 Mar 2021 · 11 MW · 3 2 Mar 2021 · 11 MW · 2 4 Mar 2021 · 8 MW · 4 5 Mar 2021 · 181 MW · 11 6 Mar 2021 · 11 MW · 4 10 Mar 2021 · 2 MW · 1 11 Mar 2021 · 2 MW · 1
26 Feb 1 Mar 5 Mar 11 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

34°high
46km/h · peak gust
17%lowest humidity

It had gone one day without rain (1 mm or more) when it started.

This area had burned before

99% of the perimeter overlaps earlier fires recorded since 2016: 725 ha in 2016, 1,045 ha in 2017, 461 ha in 2018, 753 ha in 2019, 869 ha in 2020. Part of it burned more than once, so the yearly figures add up to more than the 1,022 ha that had burned before.

How big is it?

10 km
It burned the equivalent of 0.7% of the area of London (10 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. Pang Mapha ปางมะผ้า where it started
    964 ha reached on 26 Feb
    0.9 %
  2. Pai ปาย
    75 ha reached on 11 Mar
    0.0 %

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 area0.40 ha
Residents≈ 70

Inside the perimeter there were about 0.40 hectares of built-up land and about 70 residents (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)
23 Feb 32.0 °C 38 % 26 km/h 0.2 mm Moderate 18
24 Feb 31.4 °C 38 % 43 km/h 0.0 mm Moderate 21
25 Feb 32.2 °C 28 % 39 km/h 0.0 mm High 25
26 Feb 31.7 °C 24 % 39 km/h 0.0 mm High 28
27 Feb 30.1 °C 30 % 33 km/h 0.0 mm High 27
28 Feb 31.4 °C 28 % 31 km/h 0.0 mm High 27
1 Mar 32.7 °C 26 % 27 km/h 0.0 mm High 27
2 Mar 32.7 °C 20 % 37 km/h 0.0 mm High 32
3 Mar 32.4 °C 29 % 45 km/h 0.0 mm High 34
4 Mar 33.1 °C 23 % 46 km/h 0.0 mm High 35
5 Mar 32.7 °C 18 % 41 km/h 0.0 mm High 36
6 Mar 32.4 °C 17 % 35 km/h 0.0 mm High 35
7 Mar 32.8 °C 18 % 32 km/h 0.0 mm High 35
8 Mar 32.8 °C 21 % 34 km/h 0.0 mm High 36
9 Mar 33.5 °C 21 % 26 km/h 0.0 mm High 34
10 Mar 33.1 °C 27 % 32 km/h 0.0 mm High 34
11 Mar 33.6 °C 27 % 25 km/h 0.0 mm High 33
12 Mar after 34.2 °C 26 % 27 km/h 0.0 mm High 34
13 Mar after 35.0 °C 21 % 18 km/h 0.0 mm High 32
14 Mar after 33.4 °C 31 % 32 km/h 0.0 mm High 34
15 Mar after 34.7 °C 26 % 34 km/h 0.0 mm High 35
16 Mar after 35.2 °C 22 % 31 km/h 0.0 mm High 35
17 Mar after 35.8 °C 23 % 31 km/h 0.0 mm High 35
18 Mar after 35.8 °C 25 % 29 km/h 0.0 mm High 35
19 Mar after 36.2 °C 26 % 34 km/h 0.0 mm High 36
20 Mar after 36.9 °C 23 % 37 km/h 0.0 mm High 38
21 Mar after 37.9 °C 21 % 31 km/h 0.0 mm Very high 38

Its twins: fires that started in the same weather

It started with an FWI of 17.8, a minimum humidity of 38% and 1 day without rain. Fires in the area that started in weather like this since 2016: 35.

FWI at the start 17.8
Minimum humidity 38 %
Days without rain 1
this fire chosen twins rest of the area
Almost identicalSimilar

Outlines of the closest twins

Shadaw fire, March 2023
18,468 ha 30 days FWI 18.1 Min. humidity 39 % 69 km away, in 2023

First rain (1 mm or more) after it ended: 1.8 mm on 20 Apr.

What happened to them

11 days
median duration
2,300 ha
median area
100 %
went past 1,000 ha
2.4 mm
rain at the end (median; 16 of 35 had it)

It stayed below its twins: 1,035 ha against a median of 2,300 ha. It lasted 17 days, against 11 days.

In 19 of 35, not even 1 mm fell in the ten days after the end: they went out without rain. In the rest, the first rainy day brought a median of 2.4 mm.

This is a bank of analogues: it shows what usually happens, not what will happen. With fewer than 15 twins we give no figures. How we calculate it

How it ended

—first rain
—no rain in ten days
46km/h · max. gust

It was considered over on 11 Mar, and not even 1 mm fell in the following ten days: it went out without rain. Twins with rain when they ended: 16 of 35, with a median of 2.4 mm.

Weather on this page: Open-Meteo.com (CC BY 4.0) · Copernicus Climate Change Service (ERA5)

How a twin is chosen

  • Same area: fires that have already ended, less than 250 km from this one, since 2016.
  • Same start: we compare the FWI on the first day, the minimum humidity that day and the run of days without rain before it. The slider sets how much they may differ.
  • Only pages with final weather data (ERA5 reanalysis) calculated in the same way as this fire’s; agricultural and grass burns and pages with data under review are left out.
  • Fires burning at the same time as this one (a week before or after) are left out: they share the same spell of weather and do not count as a precedent.
  • They are sorted by similarity, and the outlines of the first five are drawn.

How we calculate it

Before and after, from space

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

Before · 16 Feb 2021
After · 18 Mar 2021

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 · 28Every 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 Pang Mapha fire last?
According to the heat detections seen by satellite inside the perimeter, it burned from 23 February 2021 to 11 March 2021 (17 days). The perimeter dates it from 27 February 2021 to 6 March 2021.
How much area did it burn?
The perimeter GWIS (Copernicus) rebuilt from heat detections is 1,035 hectares (10.4 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire entered 2 municipalities: Pang Mapha (964 ha, 0.9 %); Pai (75 ha, 0.0 %).
What was the weather like?
During the fire the temperature reached 33.6 °C, humidity dropped to 17 % and gusts hit 46 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.
How did the fires that started in similar weather in this area end?
Fires less than 250 km away that started since 2016 with a similar FWI, humidity and dry spell: 35. Their median duration was 11 days and their median area 2,300 ha; 100 % went past 1,000 ha. In 19 of 35, not even 1 mm fell in the ten days after the end: they went out without rain. In the rest, the first rainy day brought a median of 2.4 mm.

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 · 2 Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.
  1. Last day with fire: 6 March 2021 → 11 March 2021.
  2. Start date: 27 February 2021 → 23 February 2021.

RSS Changes to this page With cross-checks and a citable version

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 adjusted with the VIIRS detections inside the perimeter, which said 27 February 2021 to 6 March 2021. 28 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.