Mae Suai fire, 30 March 2023 แม่สรวย · Mae Suai
The fire started on 30 March 2023 in Mae Suai, Thailand, and satellites saw it burning for 21 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 2,990 hectares from heat detections, spread across a single municipality.
It is the 42th largest in Chiang Rai Province since 2016 (of 187 with a page). Number 54 in Thailand in 2023, of 369.
The power measured by the satellite is low (23.0 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…
- Burnt area
- 2,990ha
- GWIS perimeter (Copernicus)
- Duration
- 21days
- 30 Mar 2023 – 19 Apr 2023
- Municipalities hit
- 1
- districts
- Started on
- 30 Mar
- 2023
- Heat detections
- 132
- in a single hotspot: 23 MW
- Danger at start
- 27
- High · FWI index
- Average daily power
- 33MW
- detected power per day, on average
Where it burned
How it evolved, day by day
Fire radiative power detected each day, in megawatts, and number of hotspots. The magenta bar marks the peak day.
The weather it burned in
It had gone 10 days without rain (1 mm or more) when it started. Rain came after the fire: 1.2 mm on 22 Apr.
This area had burned before
97% of the perimeter overlaps earlier fires recorded since 2016: 2,760 ha in 2016, 3,022 ha in 2019, 855 ha in 2020, 173 ha in 2022. Part of it burned more than once, so the yearly figures add up to more than the 2,912 ha that had burned before.
- 2,760 ha Mae Suai fire, April 2016 21,629 ha in total; the hectares shown are those it shares with this fire
- 2,485 ha Mae Suai fire, March 2019 10,574 ha in total; the hectares shown are those it shares with this fire
- 35 ha Mae Suai fire, March 2020 1,202 ha in total; the hectares shown are those it shares with this fire
- 30 ha Mae Suai fire, April 2020 2,380 ha in total; the hectares shown are those it shares with this fire
- 8 ha Mae Suai fire, April 2019 1,796 ha in total; the hectares shown are those it shares with this fire
How big is it?
London boundary: geoBoundaries · Office for National Statistics (Open Government Licence v3.0).
Bangkok boundary: geoBoundaries · OpenStreetMap, Wambacher · © OpenStreetMap contributors (ODbL 1.0).
Paris boundary: geoBoundaries · Institut national de l'information géographique et forestière (IGN-F) (Etalab Open License 2.0).
Madrid boundary: geoBoundaries · Open Data ESRI, IGN Central Registry of Cartography Area (CC BY 4.0).
This compares size, not location: both shapes are at the same scale, north up, centred on each other.
What happened to each town
-
3,006 ha reached on 31 Mar2.1 %
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) |
|---|---|---|---|---|---|
| 31 Mar | 34.7 °C | 26 % | 27 km/h | 0.0 mm | High 27 |
| 1 Apr | 35.0 °C | 29 % | 34 km/h | 0.0 mm | High 30 |
| 2 Apr | 34.9 °C | 25 % | 44 km/h | 0.0 mm | High 33 |
| 3 Apr | 33.8 °C | 26 % | 42 km/h | 0.0 mm | High 33 |
| 4 Apr | 35.2 °C | 22 % | 37 km/h | 0.0 mm | High 33 |
| 5 Apr | 35.2 °C | 21 % | 26 km/h | 0.0 mm | High 30 |
| 6 Apr | 35.0 °C | 27 % | 18 km/h | 0.0 mm | High 32 |
| 7 Apr | 36.1 °C | 27 % | 22 km/h | 0.0 mm | High 31 |
| 8 Apr | 35.6 °C | 31 % | 24 km/h | 0.0 mm | High 30 |
| 9 Apr | 37.6 °C | 26 % | 26 km/h | 0.0 mm | High 32 |
| 10 Apr | 37.8 °C | 24 % | 24 km/h | 0.0 mm | High 31 |
| 11 Apr | 37.5 °C | 26 % | 26 km/h | 0.0 mm | High 31 |
| 12 Apr | 37.3 °C | 24 % | 24 km/h | 0.0 mm | High 32 |
| 13 Apr | 37.6 °C | 29 % | 25 km/h | 0.0 mm | High 33 |
| 14 Apr | 38.6 °C | 23 % | 26 km/h | 0.0 mm | High 35 |
| 15 Apr | 38.1 °C | 22 % | 21 km/h | 0.0 mm | High 33 |
| 16 Apr | 38.0 °C | 25 % | 28 km/h | 0.0 mm | High 36 |
| 17 Apr | 37.9 °C | 29 % | 29 km/h | 0.0 mm | High 37 |
| 18 Apr | 38.8 °C | 27 % | 28 km/h | 0.0 mm | High 37 |
| 19 Apr | 38.0 °C | 27 % | 33 km/h | 0.0 mm | Very high 38 |
| 20 Apr after | 37.7 °C | 27 % | 30 km/h | 0.0 mm | Very high 39 |
| 21 Apr after | 37.0 °C | 28 % | 27 km/h | 0.0 mm | High 37 |
| 22 Apr after | 36.2 °C | 29 % | 31 km/h | 1.2 mm | High 30 |
Before and after, from space
Drag the line to compare the same ground before the fire and after it.
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 · CopernicusOn 12 April 2023 the air beside the fire reached 130 µg/m³ of PM2.5. That day averaged 93: 6.2 times the WHO daily guideline (15).
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 · 132Every satellite heat detection, one by one, with time, satellite, power and coordinates.
| Date and time | Satellite | FRP (MW) | Lat | Lon |
|---|
Other fires nearby
- 21,629 haMae Suai แม่สรวย1 April 2016 · 27 days · 4 km away
- 12,910 haPhan พานMarch 2026 · 29 days · 16 km away
- 10,878 haMae Lao แม่ลาวMarch 2026 · 28 days · 20 km away
- 14,912 haMae Suai แม่สรวย25 March 2026 · 30 days · 26 km away
- 12,293 haPhrao พร้าว23 March 2026 · 33 days · 34 km away
- 23,457 haMae Lao แม่ลาวMarch 2023 · 34 days · 36 km away
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 30 March 2023 to 19 April 2023 (21 days). The perimeter dates it from 5 April 2023 to 12 April 2023.
- How much area did it burn?
- The perimeter GWIS (Copernicus) rebuilt from heat detections is 2,990 hectares (29.9 km²). It is an estimate: official national figures may differ.
- Which municipalities burned?
- The fire only entered Mae Suai (3,006 ha, 2.1 %).
- What was the weather like?
- During the fire the temperature reached 37.8 °C, humidity dropped to 21 % and gusts hit 44 km/h. The fire danger index (FWI) reached 33, 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.
- Last day with fire: 12 April 2023 → 19 April 2023.
- Start date: 5 April 2023 → 30 March 2023.
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
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 5 April 2023 to 12 April 2023. 132 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.
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.