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Mae Suai fire, January 2023 แม่สรวย · Mae Suai

Out · last detection 15 Feb 2023, 07:03 UTC

The fire started on 27 January 2023 in Mae Suai, Thailand, and satellites saw it burning for 20 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 2,304 hectares from heat detections, spread across a single municipality.

It is the 56th largest in Chiang Rai Province since 2016 (of 187 with a page). Number 87 in Thailand in 2023, of 369.

Compare with…
Burnt area
2,304ha
GWIS perimeter (Copernicus)
Duration
20days
27 Jan 2023 – 15 Feb 2023
Municipalities hit
1
districts
Started on
27 Jan
2023
Heat detections
73
in a single hotspot: 115 MW
Danger at start
16
Moderate · FWI index
Average daily power
78MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 27 Jan15 Feb
15 Feb 2023

How it evolved, day by day

27 Jan 2023 · 4 MW · 1 30 Jan 2023 · 9 MW · 2 1 Feb 2023 · 16 MW · 1 2 Feb 2023 · 606 MW · 23 4 Feb 2023 · 102 MW · 7 5 Feb 2023 · 17 MW · 2 6 Feb 2023 · 99 MW · 16 7 Feb 2023 · 115 MW · 8 8 Feb 2023 · 42 MW · 5 9 Feb 2023 · 4 MW · 1 10 Feb 2023 · 16 MW · 3 12 Feb 2023 · 17 MW · 1 14 Feb 2023 · 38 MW · 2 15 Feb 2023 · 2 MW · 1
27 Jan 1 Feb 2 Feb 4 Feb 6 Feb 8 Feb 10 Feb 14 Feb

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
36km/h · peak gust
19%lowest humidity

It had gone 27 days without rain (1 mm or more) when it started. Rain came after the fire: 5.5 mm on 16 Feb.

This area had burned before

94% of the perimeter overlaps earlier fires recorded since 2016: 1,576 ha in 2016, 511 ha in 2017, 290 ha in 2018, 2,252 ha in 2019, 1,103 ha in 2020, 888 ha in 2021, 1,308 ha in 2022. Part of it burned more than once, so the yearly figures add up to more than the 2,177 ha that had burned before.

How big is it?

10 km
It burned the equivalent of 1.5% of the area of London (23 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
    2,316 ha reached on 27 Jan
    1.6 %

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.

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)
27 Jan 28.6 °C 45 % 29 km/h 0.0 mm Moderate 16
28 Jan 24.8 °C 52 % 28 km/h 0.0 mm Moderate 14
29 Jan 23.7 °C 46 % 36 km/h 0.0 mm Moderate 15
30 Jan 25.7 °C 39 % 28 km/h 0.0 mm Moderate 15
31 Jan 29.4 °C 38 % 16 km/h 0.0 mm Moderate 16
1 Feb 30.7 °C 39 % 17 km/h 0.0 mm Moderate 17
2 Feb 31.1 °C 41 % 22 km/h 0.0 mm Moderate 16
3 Feb 31.4 °C 36 % 26 km/h 0.0 mm Moderate 18
4 Feb 32.1 °C 38 % 29 km/h 0.0 mm Moderate 19
5 Feb 32.5 °C 32 % 30 km/h 0.0 mm High 22
6 Feb 33.5 °C 23 % 35 km/h 0.0 mm High 27
7 Feb 32.6 °C 21 % 34 km/h 0.0 mm High 28
8 Feb 31.6 °C 22 % 24 km/h 0.0 mm High 27
9 Feb 31.1 °C 25 % 25 km/h 0.0 mm High 27
10 Feb 31.9 °C 19 % 26 km/h 0.0 mm High 29
11 Feb 32.3 °C 22 % 24 km/h 0.0 mm High 29
12 Feb 32.5 °C 26 % 20 km/h 0.0 mm High 29
13 Feb 32.3 °C 27 % 18 km/h 0.0 mm High 29
14 Feb 31.7 °C 29 % 22 km/h 0.0 mm High 28
15 Feb 30.6 °C 48 % 38 km/h 0.6 mm High 23
16 Feb after 28.0 °C 56 % 29 km/h 5.5 mm Very low 3

Before and after, from space

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

Before · 20 Jan 2023
After · 22 Feb 2023

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 31 January 2023 the air beside the fire reached 44 µg/m³ of PM2.5. That day averaged 32: 2.1 times the WHO daily guideline (15).

PM2.5 peak44 µg/m³
Days over the guideline10 days
PM1063 µg/m³
Optical depth0.49
303112345678910111213
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 · 73Every 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 27 January 2023 to 15 February 2023 (20 days). The perimeter dates it from 1 February 2023 to 10 February 2023.
How much area did it burn?
The perimeter GWIS (Copernicus) rebuilt from heat detections is 2,304 hectares (23.0 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire only entered Mae Suai (2,316 ha, 1.6 %).
What was the weather like?
During the fire the temperature reached 33.5 °C, humidity dropped to 19 % and gusts hit 36 km/h. The fire danger index (FWI) reached 29, 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

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: 10 February 2023 → 15 February 2023.
  2. Start date: 1 February 2023 → 27 January 2023.

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.
  • Dates adjusted with the VIIRS detections inside the perimeter, which said 1 February 2023 to 10 February 2023. 73 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.

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.