How long did the Mae Suai fire last?

According to the heat detections seen by satellite inside the perimeter, it burned from 13 March 2019 to 5 April 2019 (24 days). The perimeter dates it from 20 March 2019 to 5 April 2019.

How much area did it burn?

The perimeter GWIS (Copernicus) rebuilt from heat detections is 10,574 hectares (105.7 km²). It is an estimate: official national figures may differ.

Which municipalities burned?

The fire entered 2 municipalities: Mae Suai (10,159 ha, 7.2 %); Mae Ai (473 ha, 0.6 %).

What was the weather like?

During the fire the temperature reached 36.4 °C, humidity dropped to 18 % and gusts hit 48 km/h. The fire danger index (FWI) reached 41, 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.

TH · Thailand · 2019-03-13 → 2019-04-05

Mae Suai fire, 13 March 2019 แม่สรวย · Mae Suai, Mae Ai

Out · last detection 5 Apr 2019, 19:06 UTC

The fire started on 13 March 2019 in Mae Suai, Thailand, and satellites saw it burning for 24 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 10,574 hectares from heat detections, spread across 2 municipalities.

It is the 11th largest in Chiang Rai Province since 2016 (of 187 with a page). Number 11 in Thailand in 2019, of 385.

Compare with…

Suggestions: Mae Suai · 2016 Phan · 2026 Mae Suai · 2026 Mae Lao · 2026

Burnt area: 10,574ha; GWIS perimeter (Copernicus)
Duration: 24days; 13 Mar 2019 – 5 Apr 2019
Municipalities hit: 2; districts
Started on: 13 Mar; 2019
Heat detections: 376; in a single hotspot: 39 MW
Danger at start: 33; High · FWI index
Average daily power: 57MW; detected power per day, on average

HOTSPOTS BY DAY 13 Mar5 Apr

Play back 5 Apr 2019

How it evolved, day by day

13 Mar 17 Mar 22 Mar 26 Mar 29 Mar 30 Mar 3 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

36°high

48km/h · peak gust

18%lowest humidity

It had gone 24 days without rain (1 mm or more) when it started.

This area had burned before

82% of the perimeter overlaps earlier fires recorded since 2016: 8,856 ha in 2016, 367 ha in 2018. Part of it burned more than once, so the yearly figures add up to more than the 8,708 ha that had burned before.

6,852 ha Mae Suai fire, April 2016 21,629 ha in total; the hectares shown are those it shares with this fire

How big is it?

It burned the equivalent of 6.7% of the area of London (106 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 Suai แม่สรวย where it started

10,159 ha reached on 13 Mar

7.2 %
Mae Ai แม่อาย

473 ha reached on 29 Mar

0.6 %

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 area0.35 ha

Residents≈ 40

Inside the perimeter there were about 0.35 hectares of built-up land and about 40 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	Danger (FWI)
13 Mar	33.4 °C	22 %	24 km/h	High 33
14 Mar	33.0 °C	30 %	21 km/h	High 32
15 Mar	33.4 °C	30 %	19 km/h	High 31
16 Mar	34.6 °C	28 %	22 km/h	High 33
17 Mar	35.5 °C	24 %	26 km/h	High 33
18 Mar	35.1 °C	25 %	25 km/h	High 33
19 Mar	34.7 °C	24 %	48 km/h	Very high 41
20 Mar	34.9 °C	22 %	44 km/h	Very high 41
21 Mar	35.0 °C	22 %	29 km/h	High 36
22 Mar	34.0 °C	24 %	26 km/h	High 34
23 Mar	34.1 °C	26 %	20 km/h	High 34
24 Mar	35.3 °C	24 %	29 km/h	High 37
25 Mar	34.9 °C	31 %	27 km/h	High 36
26 Mar	34.3 °C	33 %	28 km/h	High 33
27 Mar	34.5 °C	27 %	38 km/h	High 37
28 Mar	34.5 °C	26 %	42 km/h	Very high 38
29 Mar	35.1 °C	18 %	28 km/h	Very high 39
30 Mar	34.6 °C	25 %	19 km/h	High 36
31 Mar	35.0 °C	28 %	33 km/h	Very high 39
1 Apr	35.9 °C	21 %	32 km/h	Very high 38
2 Apr	35.3 °C	26 %	29 km/h	High 38
3 Apr	35.4 °C	27 %	29 km/h	High 38
4 Apr	36.4 °C	20 %	22 km/h	High 36
5 Apr	36.1 °C	22 %	24 km/h	High 37
6 Apr after	35.4 °C	28 %	26 km/h	High 37
7 Apr after	36.4 °C	25 %	34 km/h	Very high 40
8 Apr after	36.9 °C	20 %	38 km/h	Very high 40
9 Apr after	36.8 °C	23 %	32 km/h	Very high 40
10 Apr after	37.4 °C	21 %	35 km/h	Very high 41
11 Apr after	37.3 °C	22 %	28 km/h	Very high 39
12 Apr after	37.1 °C	24 %	28 km/h	Very high 39
13 Apr after	37.7 °C	23 %	28 km/h	Very high 40
14 Apr after	38.0 °C	25 %	34 km/h	Very high 42
15 Apr after	38.3 °C	23 %	32 km/h	Very high 42

Before and after, from space

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

↔

Before · 6 Mar 2019

After · 12 Apr 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 · 376Every 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 Mae Suai fire last?: According to the heat detections seen by satellite inside the perimeter, it burned from 13 March 2019 to 5 April 2019 (24 days). The perimeter dates it from 20 March 2019 to 5 April 2019.
How much area did it burn?: The perimeter GWIS (Copernicus) rebuilt from heat detections is 10,574 hectares (105.7 km²). It is an estimate: official national figures may differ.
Which municipalities burned?: The fire entered 2 municipalities: Mae Suai (10,159 ha, 7.2 %); Mae Ai (473 ha, 0.6 %).
What was the weather like?: During the fire the temperature reached 36.4 °C, humidity dropped to 18 % and gusts hit 48 km/h. The fire danger index (FWI) reached 41, 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

NASA FIRMS ↗
GWIS · Copernicus ↗

History of this page · 1 Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.

26 October 2026 Start date: 20 March 2019 → 13 March 2019.

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?

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.

How we know this

Perimeter: GWIS (Copernicus), rebuilt from heat detections rather than mapped on imagery; 2 polygons grouped in this page.
Dates adjusted with the VIIRS detections inside the perimeter, which said 20 March 2019 to 5 April 2019. 376 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