Burned area
satellite only2,494ha
Perimeter published by GWIS (Copernicus).
- Source
- GWIS (Copernicus)
- Date
- 2 Apr 2024 – 7 Apr 2024
+− cross-check
No official record is matched to this page to compare it with.
TH · Thailand · –
Mae Sariang fire, 2 April 2024 แม่สะเรียง · Mae Sariang
Out · last detection 8 Apr 2024, 18:55 UTC
The fire started on 2 April 2024 in Mae Sariang, Thailand, and satellites saw it burning for 6 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 2,494 hectares from heat detections, spread across a single municipality.
It is the 98th largest in Mae Hong Son Province since 2016 (of 361 with a page). Number 64 in Thailand in 2024, of 277.
Use this data
Compare with…
Use this data
Fire page data · version 2026-10-27matches the official recordwith caveatssatellite onlymodel
When copying, the sentence is
Tick the figures you want: they make up the lede and the CSV.
Duration by satellite
satellite only6days
2 Apr 2024 to 7 Apr 2024: first and last day with fire on the page.
- Source
- GWIS (Copernicus) · NASA FIRMS · VIIRS
- Date
- last detection: 8 Apr 2024, 18:55 UTC
+− cross-check
Satellites pass a few times a day and cloud or smoke can hide the fire: a lack of detections is not an official extinction. Each country’s emergency service declares a fire contained or out.
Start
satellite only2 Apr 2024
First day with fire seen by the satellites or the perimeter.
- Source
- GWIS (Copernicus) · NASA FIRMS · VIIRS
- Date
- 2 Apr 2024
+− cross-check
No official record is matched to this page, so the alert time and the cause are not known here.
The worst day
satellite only94MW
Total radiative power on 4 April 2024; hotspots that day: 14.
- Source
- NASA FIRMS · VIIRS (FRP)
- Date
- 4 Apr 2024
+− cross-check
Fire radiative power (FRP) measures the energy the fire gives off when the satellite passes. Added up by day, it compares intensity, not area.
Danger at the start
model38.6FWI · very high
Fire Weather Index (Canadian system) computed by WorldFires for the day the fire started. Consecutive days without rain before: 11.
- Source
- WorldFires calculation (Canadian FWI system)
- Date
- 2 Apr 2024, local noon
- Model
- ERA5 0,25° (ECMWF · Copernicus C3S) · Open-Meteo.com
+− cross-check
This is an index computed from weather model data, not a measurement of the fire nor an official warning. Danger warnings are issued by each country’s authority. Emergency number and official warnings
Weather during the fire
model39.1°C · 35% RH
High of 39.1 °C and minimum humidity of 35% on 5 April 2024; gusts of 36 km/h on 2 April 2024.
- Source
- weather model at the fire’s grid cell
- Date
- 2 Apr 2024 – 7 Apr 2024
- Model
- ERA5 0,25° (ECMWF · Copernicus C3S) · Open-Meteo.com
+− cross-check
These are model values for a cell of about 25 km, not from a weather station: they may differ from what was measured on the ground.
This page’s change log has been kept since 24 October 2026: every night what it publishes is compared and the difference is logged. Anything earlier is reconstructed from each source’s date and marked as reconstructed.
Show
-
· reconstructed weatherWeather and FWI computed from the ERA5 reanalysis
-
logLast day with fire: 9 April 2024 → 7 April 2024.
-
logStart date: 27 March 2024 → 2 April 2024.
-
logLast day with fire: 7 April 2024 → 9 April 2024.
-
logStart date: 2 April 2024 → 27 March 2024.
-
· reconstructed GHSLPopulation and built-up area computed
Area logged each night
Move the slider to see which area the page published each day.
Versioned permanent link
https://worldfires.org/en/fire/mae-sariang-2024-04?v=2026-10-27A version keeps the area, dates, name and official record; the area as it was logged (changes under 2% are not logged). The map, hotspots and weather always show today’s data.
Citation
A lede of about 60 words figures only, no adjectives
CSV for this fire mae-sariang-2024-04.csv · daily, no individual hotspots
| fecha | focos_viirs | frp_mw | tmax_c | tmin_c | hr_min_pct | viento_max_kmh | racha_max_kmh | precip_mm | fwi | clase_fwi | dentro_del_incendio |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 2024-04-02 | 17 | 27 | 38.3 | 23.1 | 31 | 11.2 | 35.6 | 0 | 38.6 | muy_alto | 1 |
| 2024-04-03 | 24 | 73 | 37.8 | 23.8 | 36 | 10.5 | 33.1 | 0 | 35 | alto | 1 |
| 2024-04-04 | 14 | 94 | 38.3 | 23.9 | 35 | 9.9 | 29.5 | 0 | 34.8 | alto | 1 |
| 2024-04-05 | 4 | 14 | 39.1 | 24.1 | 35 | 10.5 | 32.8 | 0.1 | 35.6 | alto | 1 |
| 2024-04-06 | 12 | 41 | 38.8 | 24.6 | 39 | 10.8 | 32.8 | 0.1 | 34.3 | alto | 1 |
| 2024-04-07 | 22 | 63 | 37.5 | 24.7 | 44 | 11.2 | 35.3 | 0 | 31.4 | alto | 1 |
| 2024-04-08 | 6 | 9 | 38.3 | 23.8 | 39 | 9.1 | 28.8 | 0.2 | 30 | alto | 0 |
| 2024-04-09 | 0 | 0 | 38.4 | 24.5 | 39 | 9.5 | 33.8 | 3.6 | 13 | moderado | 0 |
It is generated in your browser from this page’s data: one file per fire, aggregated by day and without individual hotspots.
Live widget for your story
It updates itself while the fire is still active and links to this page. Free, with the attribution shown at the bottom.
Sources for this page: GWIS (Copernicus), NASA FIRMS (VIIRS), ERA5 (ECMWF/Copernicus C3S) · Open-Meteo.com (CC BY 4.0), GHSL (JRC). Open-Meteo.com · How we build fire pages: methodology
- Burnt area
- 2,494ha
- GWIS perimeter (Copernicus)
- Duration
- 6days
- 2 Apr 2024 – 7 Apr 2024
- Municipalities hit
- 1
- districts
- Started on
- 2 Apr
- 2024
- Heat detections
- 99
- in a single hotspot: 0 MW
- Danger at start
- 39
- Very high · FWI index
- Average daily power
- 46MW
- detected power per day, on average
Where it burned
HOTSPOTS BY DAY
2 Apr7 Apr
8 Apr 2024
How it evolved, day by day
2 Apr
4 Apr
6 Apr
8 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
36km/h · peak gust
31%lowest humidity
It had gone 11 days without rain (1 mm or more) when it started. Rain came after the fire: 3.6 mm on 9 Apr.
This area had burned before
100% of the perimeter overlaps earlier fires recorded since 2016: 970 ha in 2016, 925 ha in 2017, 1,184 ha in 2018, 2,241 ha in 2019, 1,482 ha in 2020, 2,250 ha in 2021, 1 ha in 2022, 1,472 ha in 2023. Part of it burned more than once, so the yearly figures add up to more than the 2,507 ha that had burned before.
- 2,241 ha Mae Sariang fire, February 2019 87,620 ha in total; the hectares shown are those it shares with this fire
- 2,229 ha Mae Sariang fire, February 2021 8,248 ha in total; the hectares shown are those it shares with this fire
- 1,292 ha Mae Sariang fire, March 2023 8,462 ha in total; the hectares shown are those it shares with this fire
- 736 ha Mae Sariang fire, March 2017 1,349 ha in total; the hectares shown are those it shares with this fire
- 415 ha Mae Sariang fire, March 2020 4,038 ha in total; the hectares shown are those it shares with this fire
- 389 ha Mae Sariang fire, March 2018 22,090 ha in total; the hectares shown are those it shares with this fire
- 126 ha Mae Sariang fire, March 2016 1,211 ha in total; the hectares shown are those it shares with this fire
- 50 ha Mae Sariang fire, March 2016 2,043 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
-
2,505 ha1.0 %
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 2025Built-up area< 0.1 ha
Residents< 20
Inside the perimeter there was no noticeable built-up land and almost nobody lived there (GHSL 2025, 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. The GHSL 2025 epoch is a projection made from 2020 and earlier data.
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) |
|---|---|---|---|---|---|
| 2 Apr | 38.3 °C | 31 % | 36 km/h | 0.0 mm | Very high 39 |
| 3 Apr | 37.8 °C | 36 % | 33 km/h | 0.0 mm | High 35 |
| 4 Apr | 38.3 °C | 35 % | 30 km/h | 0.0 mm | High 35 |
| 5 Apr | 39.1 °C | 35 % | 33 km/h | 0.1 mm | High 36 |
| 6 Apr | 38.8 °C | 39 % | 33 km/h | 0.1 mm | High 34 |
| 7 Apr | 37.5 °C | 44 % | 35 km/h | 0.0 mm | High 31 |
| 8 Apr after | 38.3 °C | 39 % | 29 km/h | 0.2 mm | High 30 |
| 9 Apr after | 38.4 °C | 39 % | 34 km/h | 3.6 mm | Moderate 13 |
Its twins: fires that started in the same weather
It started with an FWI of 38.6, a minimum humidity of 31% and 11 days without rain. Fires in the area that started in weather like this since 2016: 35.
FWI at the start
38.6
Minimum humidity
31 %
Days without rain
11
this fire
chosen twins
rest of the area
Almost identicalSimilar
Outlines of the closest twins
This fire · Mae Sariang fire, 2 April 2024
2,494 ha
6 days
FWI 38.6
Min. humidity 31 %
Pai fire, April 2023
4,149 ha
4 days
FWI 38.5
Min. humidity 32 %
135 km away, in 2023
First rain (1 mm or more) after it ended: none in the following ten days.
Mae Chaem fire, May 2024
1,033 ha
2 days
FWI 32.1
Min. humidity 31 %
82 km away, in 2024
First rain (1 mm or more) after it ended: 2.7 mm on 4 May.
Mae Ramat fire, April 2016
1,028 ha
5 days
FWI 34.1
Min. humidity 31 %
121 km away, in 2016
First rain (1 mm or more) after it ended: none in the following ten days.
Sam Ngao fire, March 2021
5,383 ha
11 days
FWI 36.2
Min. humidity 30 %
130 km away, in 2021
First rain (1 mm or more) after it ended: 2.6 mm on 22 Mar.
Mueang Mae Hong Son fire, March 2021
3,066 ha
8 days
FWI 33.5
Min. humidity 29 %
140 km away, in 2021
First rain (1 mm or more) after it ended: none in the following ten days.
What happened to them
- 7 days
- median duration
- 2,518 ha
- median area
- 100 %
- went past 1,000 ha
- 2.6 mm
- rain at the end (median; 5 of 35 had it)
It burned an area similar to its twins (2,494 ha against a median of 2,518 ha) and lasted 6 days, against 7 days.
In 30 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 2.6 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
3.6 mmfirst rain
9 Apr2 days after it ended
36km/h · max. gust
It was considered over on 7 Apr, and on 9 Apr 3.6 mm fell. We do not know whether the rain or the firefighters put it out. Twins with rain when they ended: 5 of 35, with a median of 2.6 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.
Before and after, from space
Drag the line to compare the same ground before the fire and after it.
↔
Before · 26 Mar 2024
After · 14 Apr 2024
Sentinel-2 did not pass over on that day. Try another date, or use false colour, which is daily.
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 10 April 2024 the air beside the fire reached 80 µg/m³ of PM2.5. That day averaged 59: 3.9 times the WHO daily guideline (15).
PM2.5 peak80 µg/m³
Days over the guideline11 days
PM10116 µg/m³
Optical depth2.02
WHO 15
31 Mar3 Apr6 Apr9 Apr
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 · 0Every 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
- 8,462 haMae Sariang แม่สะเรียง20 March 2023 · 18 days · 4 km away
- 18,375 haMae Sariang แม่สะเรียง5 March 2017 · 28 days · 14 km away
- 157,976 haMae La Noi แม่ลาน้อย18 March 2026 · 41 days · 23 km away
- 22,090 haMae Sariang แม่สะเรียง19 March 2018 · 30 days · 23 km away
- 12,437 haSop Moei สบเมย20 March 2019 · 34 days · 33 km away
- 54,550 haSop Moei สบเมย21 March 2026 · 35 days · 35 km away
Frequently asked questions
- How long did the Mae Sariang fire last?
- GWIS (Copernicus) dates it between 2 April 2024 and 7 April 2024: 6 days between the first and last heat detection of the perimeter.
- How much area did it burn?
- The perimeter GWIS (Copernicus) rebuilt from heat detections is 2,494 hectares (24.9 km²). It is an estimate: official national figures may differ.
- Which municipalities burned?
- The fire only entered Mae Sariang (2,505 ha, 1.0 %).
- What was the weather like?
- During the fire the temperature reached 39.1 °C, humidity dropped to 31 % and gusts hit 36 km/h. The fire danger index (FWI) reached 39, 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.
- 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 7 days and their median area 2,518 ha; 100 % went past 1,000 ha. In 30 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 2.6 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 · 4 Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.
- Last day with fire: 9 April 2024 → 7 April 2024.
- Start date: 27 March 2024 → 2 April 2024.
- Last day with fire: 7 April 2024 → 9 April 2024.
- Start date: 2 April 2024 → 27 March 2024.
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
How we know this
- Perimeter: GWIS (Copernicus), rebuilt from heat detections rather than mapped on imagery.
- Dates from the perimeter: the VIIRS detections inside it did not change them. No 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 2025, 100 m cells), summed inside the perimeter: an estimate of what was there, not a damage count.
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.