Li fire, 10 February 2021 ลี้ · Li, Sam Ngao
The fire started on 10 February 2021 in Li, Thailand, and satellites saw it burning for 8 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 3,710 hectares from heat detections, spread across 2 municipalities.
It is the 52th largest in Chiang Mai Province since 2016 (of 447 with a page). Number 17 in Thailand in 2021, of 235.
The power measured by the satellite is low (15.9 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
- 3,710ha
- GWIS perimeter (Copernicus)
- Duration
- 8days
- 10 Feb 2021 – 17 Feb 2021
- Municipalities hit
- 2
- districts
- Started on
- 10 Feb
- 2021
- Heat detections
- 136
- in a single hotspot: 16 MW
- Danger at start
- 21
- Moderate · FWI index
- Average daily power
- 48MW
- 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 more than two months without rain (1 mm or more) when it started.
This area had burned before
82% of the perimeter overlaps earlier fires recorded since 2016: 1,363 ha in 2016, 1,576 ha in 2017, 1,001 ha in 2019, 2,248 ha in 2020. Part of it burned more than once, so the yearly figures add up to more than the 3,026 ha that had burned before.
- 2,065 ha Li fire, January 2020 3,006 ha in total; the hectares shown are those it shares with this fire
- 866 ha Li fire, February 2019 1,129 ha in total; the hectares shown are those it shares with this fire
- 306 ha Li fire, March 2017 2,743 ha in total; the hectares shown are those it shares with this fire
- 24 ha Sam Ngao fire, February 2019 2,639 ha in total; the hectares shown are those it shares with this fire
What happened to each town
-
3,693 ha reached on 9 Feb2.0 %
-
Sam Ngao สามเงา34 ha reached on 15 Feb0.0 %
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) |
|---|---|---|---|---|---|
| 9 Feb | 28.5 °C | 29 % | 22 km/h | 0.3 mm | Moderate 21 |
| 10 Feb | 28.3 °C | 30 % | 29 km/h | 0.0 mm | High 23 |
| 11 Feb | 30.8 °C | 26 % | 21 km/h | 0.0 mm | High 26 |
| 12 Feb | 32.1 °C | 24 % | 20 km/h | 0.0 mm | High 27 |
| 13 Feb | 32.0 °C | 25 % | 28 km/h | 0.0 mm | High 28 |
| 14 Feb | 32.5 °C | 23 % | 29 km/h | 0.0 mm | High 29 |
| 15 Feb | 32.4 °C | 21 % | 28 km/h | 0.0 mm | High 32 |
| 16 Feb | 33.1 °C | 24 % | 25 km/h | 0.0 mm | High 30 |
| 17 Feb | 30.5 °C | 43 % | 34 km/h | 0.2 mm | High 26 |
| 18 Feb after | 29.9 °C | 39 % | 37 km/h | 0.0 mm | High 28 |
| 19 Feb after | 29.3 °C | 34 % | 40 km/h | 0.0 mm | High 28 |
| 20 Feb after | 30.6 °C | 33 % | 27 km/h | 0.0 mm | High 25 |
| 21 Feb after | 32.0 °C | 29 % | 22 km/h | 0.0 mm | High 27 |
| 22 Feb after | 32.6 °C | 31 % | 20 km/h | 0.0 mm | High 25 |
| 23 Feb after | 31.5 °C | 41 % | 22 km/h | 0.0 mm | High 25 |
| 24 Feb after | 32.8 °C | 34 % | 36 km/h | 0.0 mm | High 29 |
| 25 Feb after | 33.8 °C | 25 % | 34 km/h | 0.0 mm | High 33 |
| 26 Feb after | 34.6 °C | 19 % | 32 km/h | 0.0 mm | High 37 |
| 27 Feb after | 33.7 °C | 21 % | 34 km/h | 0.0 mm | High 38 |
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.
Detections table · 136Every 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 haLi ลี้23 March 2026 · 33 days · 8 km away
- 28,586 haLi ลี้20 March 2026 · 24 days · 13 km away
- 21,139 haSam Ngao สามเงา6 February 2019 · 33 days · 29 km away
- 12,196 haSam Ngao สามเงา1 March 2024 · 19 days · 29 km away
- 45,311 haSam Ngao สามเงา21 March 2026 · 35 days · 32 km away
- 12,765 haOmkoi อมก๋อย24 March 2026 · 28 days · 32 km away
Frequently asked questions
- How long did the Li fire last?
- GWIS (Copernicus) dates it between 10 February 2021 and 17 February 2021: 8 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 3,710 hectares (37.1 km²). It is an estimate: official national figures may differ.
- Which municipalities burned?
- The fire entered 2 municipalities: Li (3,693 ha, 2.0 %); Sam Ngao (34 ha, 0.0 %).
- What was the weather like?
- During the fire the temperature reached 33.1 °C, humidity dropped to 21 % and gusts hit 34 km/h. The fire danger index (FWI) reached 32, 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.