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Mae Suai fire, 15 April 2019 แม่สรวย · Mae Suai, Mueang Chiang Rai

Out · last detection 24 Apr 2019, 07:20 UTC

The fire started on 15 April 2019 in Mae Suai, Thailand, and satellites saw it burning for 10 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 3,790 hectares from heat detections, spread across 2 municipalities.

It is the 30th largest in Chiang Rai Province since 2016 (of 187 with a page). Number 38 in Thailand in 2019, of 385.

The power measured by the satellite is low (19.6 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: Mae Suai · 2016Phan · 2026Mae Lao · 2026Mae Lao · 2023

Burnt area
3,790ha
GWIS perimeter (Copernicus)
Duration
10days
15 Apr 2019 – 24 Apr 2019
Municipalities hit
2
districts
Started on
15 Apr
2019
Heat detections
88
in a single hotspot: 20 MW
Danger at start
42
Very high · FWI index
Average daily power
41MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 15 Apr24 Apr
24 Apr 2019

How it evolved, day by day

15 Apr 2019 · 87 MW · 6 16 Apr 2019 · 56 MW · 14 17 Apr 2019 · 14 MW · 3 18 Apr 2019 · 111 MW · 41 19 Apr 2019 · 6 MW · 3 20 Apr 2019 · 63 MW · 12 21 Apr 2019 · 6 MW · 2 22 Apr 2019 · 7 MW · 4 24 Apr 2019 · 21 MW · 3
15 Apr 17 Apr 18 Apr 19 Apr 21 Apr 24 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

39°high
35km/h · peak gust
23%lowest humidity

It had gone 57 days without rain (1 mm or more) when it started. Rain came after the fire: 1.5 mm on 23 Apr.

This area had burned before

70% of the perimeter overlaps earlier fires recorded since 2016: 2,689 ha in 2016, 53 ha in 2018.

How big is it?

10 km
It burned the equivalent of 2.4% of the area of London (38 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. Mae Suai แม่สรวย where it started
    3,545 ha reached on 15 Apr
    2.5 %
  2. Mueang Chiang Rai เมืองเชียงราย
    265 ha reached on 16 Apr
    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 area3.5 ha
Residents≈ 350

Inside the perimeter there were about 3.5 hectares of built-up land and about 350 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)
15 Apr 38.8 °C 23 % 32 km/h 0.0 mm Very high 42
16 Apr 39.0 °C 25 % 21 km/h 0.0 mm Very high 39
17 Apr 38.1 °C 26 % 30 km/h 0.0 mm Very high 41
18 Apr 38.8 °C 26 % 31 km/h 0.0 mm Very high 40
19 Apr 39.1 °C 27 % 35 km/h 0.7 mm High 37
20 Apr 38.3 °C 28 % 29 km/h 0.0 mm High 34
21 Apr 37.0 °C 30 % 29 km/h 0.0 mm High 35
22 Apr 36.2 °C 37 % 33 km/h 1.3 mm High 22
23 Apr 37.0 °C 33 % 26 km/h 1.5 mm High 22

Before and after, from space

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

Before · 8 Apr 2019
After · 1 May 2019

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 · 88Every 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 Mae Suai fire last?
According to the heat detections seen by satellite inside the perimeter, it burned from 15 April 2019 to 24 April 2019 (10 days). The perimeter dates it from 15 April 2019 to 22 April 2019.
How much area did it burn?
The perimeter GWIS (Copernicus) rebuilt from heat detections is 3,790 hectares (37.9 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire entered 2 municipalities: Mae Suai (3,545 ha, 2.5 %); Mueang Chiang Rai (265 ha, 0.2 %).
What was the weather like?
During the fire the temperature reached 39.1 °C, humidity dropped to 23 % and gusts hit 35 km/h. The fire danger index (FWI) reached 42, 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 · 1 Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.
  1. Last day with fire: 22 April 2019 → 24 April 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?

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 15 April 2019 to 22 April 2019. 88 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.