Burned area
satellite only21,683ha
Perimeter published by GWIS (Copernicus).
- Source
- GWIS (Copernicus)
- Date
- 27 Mar 2026 – 22 Apr 2026
+− cross-check
No official record is matched to this page to compare it with.
TH · Thailand · –
Lom Sak fire, 27 March 2026 หล่มสัก · Lom Sak, Mueang Phetchabun
Out · last detection 19 Apr 2026, 06:37 UTC
The fire started on 27 March 2026 in Lom Sak, Thailand, and satellites saw it burning for 27 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 21,683 hectares from heat detections, spread across 2 municipalities.
Number 23 in Thailand in 2026, of 688.
GWIS near-real-time perimeter, from the layer that changed in October 2025: this fire is not compared with fires from earlier years, because since then the GWIS layer gives more and larger perimeters.
Use this data
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Fire page data · version 2026-10-26matches 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 only27days
27 Mar 2026 to 22 Apr 2026: first and last day with fire on the page.
- Source
- GWIS (Copernicus) · NASA FIRMS · VIIRS
- Date
- last detection: 19 Apr 2026, 06:37 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 only27 Mar 2026
First day with fire seen by the satellites or the perimeter.
- Source
- GWIS (Copernicus) · NASA FIRMS · VIIRS
- Date
- 27 Mar 2026
+− cross-check
No official record is matched to this page, so the alert time and the cause are not known here.
Hotspots
satellite only617
VIIRS detections at 375 m. Most intense hotspot: 30 MW.
- Source
- NASA FIRMS · VIIRS (Suomi NPP)
- Date
- 27 Mar 2026 – 22 Apr 2026
+− cross-check
There is no official record to compare with. Each hotspot is a pixel detected in one satellite pass, not a separate fire.
The worst day
satellite only451MW
Total radiative power on 14 April 2026; hotspots that day: 105.
- Source
- NASA FIRMS · VIIRS (FRP)
- Date
- 14 Apr 2026
+− 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
model26.6FWI · high
Fire Weather Index (Canadian system) computed by WorldFires for the day the fire started. Consecutive days without rain before: 4.
- Source
- WorldFires calculation (Canadian FWI system)
- Date
- 27 Mar 2026, 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
model35.7°C · 32% RH
High of 35.7 °C and minimum humidity of 32% on 14 April 2026; gusts of 42 km/h on 11 April 2026.
- Source
- weather model at the fire’s grid cell
- Date
- 27 Mar 2026 – 22 Apr 2026
- 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.
Living inside
model≈ 250people
Estimated residents inside the perimeter and 4.0 ha of built-up area (100 m grid, epoch 2025).
- Source
- GHSL R2023A · JRC
- Date
- calculated on 24 October 2026
+− cross-check
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.
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
-
logStart date: 29 March 2026 → 27 March 2026.
-
· reconstructed GHSLPopulation and built-up area computed
What was saved on 26 October 2026
Every night a snapshot of what the page shows is saved. If anything changes, it appears in the list as a log entry.
- Area
- 21,683 ha
- Dates
- 27 Mar 2026 – 22 Apr 2026
- Name
- Lom Sak
- Official record
- —
Versioned permanent link
https://worldfires.org/en/fire/lom-sak-2026-03-3?v=2026-10-26A 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 lom-sak-2026-03-3.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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 2026-03-27 | 1 | 3 | 34.2 | 21.7 | 43 | 10.5 | 34.2 | 0 | 26.6 | alto | 1 |
| 2026-03-28 | 2 | 10 | 34.3 | 21.4 | 43 | 9.4 | 29.2 | 1.9 | 25.2 | alto | 1 |
| 2026-03-29 | 8 | 27 | 34.2 | 20.9 | 36 | 14 | 36.4 | 0.4 | 22.9 | alto | 1 |
| 2026-03-30 | 0 | 0 | 32.9 | 20.7 | 45 | 11.7 | 37.1 | 0.4 | 27.9 | alto | 1 |
| 2026-03-31 | 2 | 6 | 33.3 | 21.4 | 42 | 12 | 36 | 0 | 27.5 | alto | 1 |
| 2026-04-01 | 7 | 31 | 34.5 | 20.7 | 37 | 8.3 | 26.6 | 0 | 25.9 | alto | 1 |
| 2026-04-02 | 27 | 226 | 35.3 | 21.7 | 34 | 12 | 32 | 0 | 30.8 | alto | 1 |
| 2026-04-03 | 28 | 78 | 33.7 | 22.1 | 42 | 13.5 | 37.8 | 0 | 32.8 | alto | 1 |
| 2026-04-04 | 43 | 116 | 33.2 | 21 | 43 | 11.4 | 34.9 | 0.4 | 32.3 | alto | 1 |
| 2026-04-05 | 27 | 115 | 33.6 | 21 | 43 | 11.8 | 37.4 | 0 | 33 | alto | 1 |
| 2026-04-06 | 9 | 25 | 34.3 | 21.1 | 39 | 11.8 | 36 | 0 | 31.8 | alto | 1 |
| 2026-04-07 | 14 | 40 | 34.3 | 21.4 | 39 | 13.8 | 39.2 | 0 | 36.4 | alto | 1 |
| 2026-04-08 | 50 | 190 | 35 | 21.8 | 34 | 14.4 | 40 | 0 | 37.1 | alto | 1 |
| 2026-04-09 | 59 | 173 | 34.5 | 20.4 | 37 | 14.9 | 41.4 | 0 | 37.7 | alto | 1 |
| 2026-04-10 | 37 | 104 | 34.9 | 21 | 34 | 13.7 | 39.2 | 0 | 38.1 | muy_alto | 1 |
| 2026-04-11 | 21 | 68 | 34.4 | 21 | 34 | 15.5 | 42.5 | 0 | 40.7 | muy_alto | 1 |
| 2026-04-12 | 9 | 53 | 34.5 | 20.9 | 36 | 13.3 | 36 | 0 | 36.6 | alto | 1 |
| 2026-04-13 | 23 | 90 | 34.3 | 21.1 | 39 | 11.7 | 36 | 0.4 | 35.9 | alto | 1 |
| 2026-04-14 | 105 | 451 | 35.7 | 20.5 | 32 | 11.4 | 31.7 | 0 | 34.2 | alto | 1 |
| 2026-04-15 | 62 | 303 | 35.5 | 21.3 | 33 | 14.1 | 36.7 | 0 | 40.3 | muy_alto | 1 |
| 2026-04-16 | 38 | 208 | 35.6 | 21.3 | 33 | 9.6 | 30.2 | 0 | 35.4 | alto | 1 |
| 2026-04-17 | 16 | 71 | 34.5 | 22.2 | 36 | 11.4 | 28.4 | 0 | 34.9 | alto | 1 |
| 2026-04-18 | 10 | 34 | 33.6 | 22 | 42 | 10.2 | 24.1 | 0 | 29.6 | alto | 1 |
| 2026-04-19 | 19 | 92 | 33.1 | 22.7 | 48 | 8.9 | 27.4 | 1.5 | 31.1 | alto | 1 |
| 2026-04-20 | 0 | 0 | 32.5 | 21.9 | 49 | 7.4 | 27.4 | 0.2 | 18 | moderado | 1 |
| 2026-04-21 | 0 | 0 | 34.4 | 21.5 | 38 | 9 | 27 | 0 | 27.6 | alto | 1 |
| 2026-04-22 | 0 | 0 | 33.9 | 22.5 | 46 | 10.7 | 31.7 | 0 | 29.5 | alto | 1 |
| 2026-04-23 | 0 | 0 | 33.7 | 23 | 52 | 9.8 | 33.8 | 0.3 | 28.1 | alto | 0 |
| 2026-04-24 | 0 | 0 | 32.6 | 22.9 | 51 | 8.5 | 22.7 | 0.8 | 18.4 | moderado | 0 |
| 2026-04-25 | 0 | 0 | 27.6 | 22.7 | 71 | 9.8 | 21.6 | 5.6 | 2 | muy_bajo | 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
- 21,683ha
- GWIS perimeter (Copernicus)
- Duration
- 27days
- 27 Mar 2026 – 22 Apr 2026
- Municipalities hit
- 2
- districts
- Started on
- 27 Mar
- 2026
- Heat detections
- 617
- in a single hotspot: 30 MW
- Danger at start
- 27
- High · FWI index
- Average daily power
- 109MW
- detected power per day, on average
Where it burned
HOTSPOTS BY DAY
27 Mar22 Apr
19 Apr 2026
How it evolved, day by day
27 Mar
2 Apr
7 Apr
14 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
42km/h · peak gust
32%lowest humidity
It had gone 4 days without rain (1 mm or more) when it started. Rain came after the fire: 5.6 mm on 25 Apr.
This area had burned before
82% of the perimeter overlaps earlier fires recorded since 2016: 4,577 ha in 2016, 867 ha in 2017, 1,145 ha in 2018, 4,853 ha in 2019, 5,720 ha in 2020, 4,795 ha in 2021, 8,178 ha in 2023, 5,868 ha in 2024, 5,012 ha in 2025. Part of it burned more than once, so the yearly figures add up to more than the 17,798 ha that had burned before.
- 3,172 ha Lom Sak fire, March 2023 3,160 ha in total; the hectares shown are those it shares with this fire
- 1,919 ha Lom Sak fire, March 2025 3,223 ha in total; the hectares shown are those it shares with this fire
- 1,435 ha Mueang Phetchabun fire, February 2020 1,489 ha in total; the hectares shown are those it shares with this fire
- 1,351 ha Lom Sak fire, February 2023 1,583 ha in total; the hectares shown are those it shares with this fire
- 1,011 ha Lom Sak fire, April 2024 1,024 ha in total; the hectares shown are those it shares with this fire
- 1,008 ha Lom Sak fire, April 2024 1,043 ha in total; the hectares shown are those it shares with this fire
- 990 ha Lom Sak fire, April 2023 1,054 ha in total; the hectares shown are those it shares with this fire
- 980 ha Mueang Phetchabun fire, April 2024 1,052 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
-
20,436 ha reached on 27 Mar14 %
-
Mueang Phetchabun เมืองเพชรบูรณ์1,366 ha reached on 15 Apr0.6 %
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 2025Built-up area4.0 ha
Residents≈ 250
Inside the perimeter there were about 4.0 hectares of built-up land and about 250 residents (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) |
|---|---|---|---|---|---|
| 27 Mar | 34.2 °C | 43 % | 34 km/h | 0.0 mm | High 27 |
| 28 Mar | 34.3 °C | 43 % | 29 km/h | 1.9 mm | High 25 |
| 29 Mar | 34.2 °C | 36 % | 36 km/h | 0.4 mm | High 23 |
| 30 Mar | 32.9 °C | 45 % | 37 km/h | 0.4 mm | High 28 |
| 31 Mar | 33.3 °C | 42 % | 36 km/h | 0.0 mm | High 28 |
| 1 Apr | 34.5 °C | 37 % | 27 km/h | 0.0 mm | High 26 |
| 2 Apr | 35.3 °C | 34 % | 32 km/h | 0.0 mm | High 31 |
| 3 Apr | 33.7 °C | 42 % | 38 km/h | 0.0 mm | High 33 |
| 4 Apr | 33.2 °C | 43 % | 35 km/h | 0.4 mm | High 32 |
| 5 Apr | 33.6 °C | 43 % | 37 km/h | 0.0 mm | High 33 |
| 6 Apr | 34.3 °C | 39 % | 36 km/h | 0.0 mm | High 32 |
| 7 Apr | 34.3 °C | 39 % | 39 km/h | 0.0 mm | High 36 |
| 8 Apr | 35.0 °C | 34 % | 40 km/h | 0.0 mm | High 37 |
| 9 Apr | 34.5 °C | 37 % | 41 km/h | 0.0 mm | High 38 |
| 10 Apr | 34.9 °C | 34 % | 39 km/h | 0.0 mm | Very high 38 |
| 11 Apr | 34.4 °C | 34 % | 42 km/h | 0.0 mm | Very high 41 |
| 12 Apr | 34.5 °C | 36 % | 36 km/h | 0.0 mm | High 37 |
| 13 Apr | 34.3 °C | 39 % | 36 km/h | 0.4 mm | High 36 |
| 14 Apr | 35.7 °C | 32 % | 32 km/h | 0.0 mm | High 34 |
| 15 Apr | 35.5 °C | 33 % | 37 km/h | 0.0 mm | Very high 40 |
| 16 Apr | 35.6 °C | 33 % | 30 km/h | 0.0 mm | High 35 |
| 17 Apr | 34.5 °C | 36 % | 28 km/h | 0.0 mm | High 35 |
| 18 Apr | 33.6 °C | 42 % | 24 km/h | 0.0 mm | High 30 |
| 19 Apr | 33.1 °C | 48 % | 27 km/h | 1.5 mm | High 31 |
| 20 Apr | 32.5 °C | 49 % | 27 km/h | 0.2 mm | Moderate 18 |
| 21 Apr | 34.4 °C | 38 % | 27 km/h | 0.0 mm | High 28 |
| 22 Apr | 33.9 °C | 46 % | 32 km/h | 0.0 mm | High 30 |
| 23 Apr after | 33.7 °C | 52 % | 34 km/h | 0.3 mm | High 28 |
| 24 Apr after | 32.6 °C | 51 % | 23 km/h | 0.8 mm | Moderate 18 |
| 25 Apr after | 27.6 °C | 71 % | 22 km/h | 5.6 mm | Very low 2 |
Before and after, from space
Drag the line to compare the same ground before the fire and after it.
↔
Before · 20 Mar 2026
After · 29 Apr 2026
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 17 April 2026 the air beside the fire reached 126 µg/m³ of PM2.5. That day averaged 66: 4.4 times the WHO daily guideline (15).
PM2.5 peak126 µg/m³
Days over the guideline30 days
PM10133 µg/m³
Optical depth1.54
WHO 15
27 Mar2 Apr8 Apr14 Apr20 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 · 617Every 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
- 9,120 haLom Sak หล่มสัก28 March 2026 · 21 days · 23 km away
- 8,322 haMueang Phetchabun เมืองเพชรบูรณ์2 February 2020 · 28 days · 29 km away
- 9,733 haMueang Phetchabun เมืองเพชรบูรณ์22 March 2023 · 22 days · 31 km away
- 10,525 haPhu Kradueng ภูกระดึง4 April 2026 · 15 days · 37 km away
- 7,064 haLom Kao หล่มเก่าFebruary 2021 · 10 days · 38 km away
Frequently asked questions
- How long did the Lom Sak fire last?
- According to the heat detections seen by satellite inside the perimeter, it burned from 27 March 2026 to 22 April 2026 (27 days). The perimeter dates it from 29 March 2026 to 22 April 2026.
- How much area did it burn?
- The perimeter GWIS (Copernicus) rebuilt from heat detections is 21,683 hectares (216.8 km²). It is an estimate: official national figures may differ.
- Which municipalities burned?
- The fire entered 2 municipalities: Lom Sak (20,436 ha, 14 %); Mueang Phetchabun (1,366 ha, 0.6 %).
- What was the weather like?
- During the fire the temperature reached 35.7 °C, humidity dropped to 32 % and gusts hit 42 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
History of this page · 1 Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.
- Start date: 29 March 2026 → 27 March 2026.
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 adjusted with the VIIRS detections inside the perimeter, which said 29 March 2026 to 22 April 2026. 617 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.