Li fire, 28 March 2024 Li, Sam Ngao
The fire started on 28 March 2024 in Li, Thailand, and satellites saw it burning for 11 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 5,674 hectares from heat detections, spread across 2 municipalities.
It is the 27th largest in Chiang Mai Province since 2016 (of 463 with a page). Number 18 in Thailand in 2024, of 350.
The power measured by the satellite is low (23.4 MW in the strongest hotspot), more typical of grass or stubble burning, or a slow surface fire, than of a large crown fire.
- Burnt area
- 5,674ha
- GWIS perimeter (Copernicus)
- Duration
- 11days
- 28 Mar 2024 – 7 Apr 2024
- Municipalities hit
- 2
- districts
- Started on
- 28 Mar
- 2024
- Heat detections
- 237
- in a single hotspot: 23 MW
- Danger at start
- 29
- High · FWI index
- Energy released
- 920MW
- sum of detected power
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 4 days without rain (1 mm or more) when it started. Rain came after the fire: 4.9 mm on 11 Apr.
This area had burned before
96% of the perimeter overlaps earlier fires recorded since 2016: 1,356 ha in 2016, 2,871 ha in 2017, 2,747 ha in 2018, 1,737 ha in 2019, 2,368 ha in 2020, 2,563 ha in 2021, 2,595 ha in 2023. Part of it burned more than once, so the yearly figures add up to more than the 5,456 ha that had burned before.
- 1,494 ha Li fire, February 2023 2,612 ha in total; the hectares shown are those it shares with this fire
- 1,476 ha Li fire, March 2017 2,743 ha in total; the hectares shown are those it shares with this fire
- 1,428 ha Sam Ngao fire, February 2019 21,139 ha in total; the hectares shown are those it shares with this fire
- 1,063 ha Li fire, March 2018 1,431 ha in total; the hectares shown are those it shares with this fire
- 670 ha Li fire, March 2018 1,649 ha in total; the hectares shown are those it shares with this fire
- 571 ha Li fire, March 2016 1,309 ha in total; the hectares shown are those it shares with this fire
- 519 ha Li fire, March 2018 1,437 ha in total; the hectares shown are those it shares with this fire
- 363 ha Li fire, February 2023 5,032 ha in total; the hectares shown are those it shares with this fire
What happened to each town
-
Li where it started5,534 ha reached on 25 Mar3.1 %
-
163 ha reached on 3 Apr0.1 %
Burnt area inside each municipality, from crossing the GWIS perimeter with administrative boundaries. The distance is from the town centre 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) |
|---|---|---|---|---|---|
| 25 Mar | 37.8 °C | 17 % | 20 km/h | 0.0 mm | High 29 |
| 26 Mar | 38.6 °C | 23 % | 28 km/h | 0.0 mm | High 32 |
| 27 Mar | 36.9 °C | 28 % | 32 km/h | 0.1 mm | High 29 |
| 28 Mar | 38.1 °C | 22 % | 35 km/h | 0.0 mm | High 31 |
| 29 Mar | 36.9 °C | 27 % | 44 km/h | 0.0 mm | High 35 |
| 30 Mar | 38.0 °C | 21 % | 42 km/h | 0.0 mm | High 35 |
| 31 Mar | 37.9 °C | 24 % | 40 km/h | 0.0 mm | High 35 |
| 1 Apr | 38.7 °C | 26 % | 36 km/h | 0.0 mm | High 34 |
| 2 Apr | 39.2 °C | 27 % | 35 km/h | 0.1 mm | High 35 |
| 3 Apr | 39.0 °C | 27 % | 38 km/h | 0.0 mm | High 37 |
| 4 Apr | 39.8 °C | 28 % | 30 km/h | 0.0 mm | High 36 |
| 5 Apr | 39.9 °C | 29 % | 35 km/h | 0.0 mm | High 37 |
| 6 Apr | 39.2 °C | 33 % | 34 km/h | 0.0 mm | High 34 |
| 7 Apr | 37.7 °C | 35 % | 36 km/h | 0.1 mm | High 36 |
| 8 Apr after | 38.4 °C | 32 % | 25 km/h | 0.0 mm | High 32 |
| 9 Apr after | 39.5 °C | 32 % | 31 km/h | 0.1 mm | High 34 |
| 10 Apr after | 35.0 °C | 43 % | 33 km/h | 0.6 mm | High 28 |
| 11 Apr after | 36.0 °C | 40 % | 29 km/h | 4.9 mm | Low 6 |
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 10 April 2024 the air beside the fire reached 50 µg/m³ of PM2.5. That day averaged 39: 2.6 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 · 237Every satellite heat detection, one by one, with time, satellite, power and coordinates.
| Date and time | Satellite | FRP (MW) | Lat | Lon |
|---|
Other fires nearby
- 20,120 haLi23 March 2026 · 33 days · 18 km away
- 28,586 haLi20 March 2026 · 24 days · 19 km away
- 21,139 haSam Ngao6 February 2019 · 33 days · 19 km away
- 12,196 haSam Ngao1 March 2024 · 19 days · 20 km away
- 45,311 haSam Ngao21 March 2026 · 35 days · 24 km away
- 18,226 haSam Ngao13 March 2025 · 19 days · 24 km away
Frequently asked questions
- How long did the Li fire last?
- GWIS (Copernicus) dates it between 28 March 2024 and 7 April 2024: 11 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 5,674 hectares (56.7 km²). It is an estimate: official national figures may differ.
- Which municipalities burned?
- The fire entered 2 municipalities: Li (5,534 ha, 3.1 %); Sam Ngao (163 ha, 0.1 %).
- What was the weather like?
- During the fire the temperature reached 39.9 °C, humidity dropped to 17 % and gusts hit 44 km/h. The fire danger index (FWI) reached 37, 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
Satellite cross-check
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
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.