Li fire, 20 February 2023 Li
The fire started on 20 February 2023 in Li, Thailand, and satellites saw it burning for 4 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 1,269 hectares from heat detections, spread across a single municipality.
It is the 312th largest in Chiang Mai Province since 2016 (of 463 with a page). Number 341 in Thailand in 2023, of 500.
The power measured by the satellite is low (20.1 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
- 1,269ha
- GWIS perimeter (Copernicus)
- Duration
- 4days
- 20 Feb 2023 – 23 Feb 2023
- Municipalities hit
- 1
- districts
- Started on
- 20 Feb
- 2023
- Heat detections
- 51
- in a single hotspot: 20 MW
- Danger at start
- 21
- Moderate · FWI index
- Energy released
- 172MW
- 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 one day without rain (1 mm or more) when it started.
This area had burned before
97% of the perimeter overlaps earlier fires recorded since 2016: 40 ha in 2016, 984 ha in 2017, 51 ha in 2018, 391 ha in 2019, 421 ha in 2020, 892 ha in 2021. Part of it burned more than once, so the yearly figures add up to more than the 1,231 ha that had burned before.
- 503 ha Li fire, March 2017 3,816 ha in total; the hectares shown are those it shares with this fire
- 478 ha Li fire, February 2021 2,249 ha in total; the hectares shown are those it shares with this fire
- 133 ha Li fire, February 2020 4,067 ha in total; the hectares shown are those it shares with this fire
- 81 ha Li fire, February 2019 1,767 ha in total; the hectares shown are those it shares with this fire
What happened to each town
-
Li where it started1,275 ha reached on 20 Feb0.7 %
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) |
|---|---|---|---|---|---|
| 20 Feb | 32.0 °C | 36 % | 30 km/h | 0.0 mm | Moderate 21 |
| 21 Feb | 31.9 °C | 37 % | 35 km/h | 0.0 mm | High 22 |
| 22 Feb | 31.9 °C | 37 % | 34 km/h | 0.0 mm | High 22 |
| 23 Feb | 32.5 °C | 36 % | 23 km/h | 0.0 mm | Moderate 20 |
| 24 Feb after | 33.7 °C | 34 % | 23 km/h | 0.0 mm | High 23 |
| 25 Feb after | 30.6 °C | 44 % | 34 km/h | 0.0 mm | High 24 |
| 26 Feb after | 29.3 °C | 39 % | 41 km/h | 0.0 mm | High 26 |
| 27 Feb after | 29.1 °C | 36 % | 33 km/h | 0.0 mm | High 23 |
| 28 Feb after | 30.9 °C | 29 % | 26 km/h | 0.0 mm | High 24 |
| 1 Mar after | 32.8 °C | 32 % | 27 km/h | 0.0 mm | High 25 |
| 2 Mar after | 33.2 °C | 30 % | 28 km/h | 0.0 mm | High 26 |
| 3 Mar after | 32.7 °C | 35 % | 27 km/h | 0.0 mm | High 27 |
| 4 Mar after | 31.3 °C | 38 % | 30 km/h | 0.0 mm | High 27 |
| 5 Mar after | 31.4 °C | 39 % | 26 km/h | 0.0 mm | High 26 |
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 23 February 2023 the air beside the fire reached 34 µg/m³ of PM2.5. That day averaged 23: 1.5 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 · 51Every satellite heat detection, one by one, with time, satellite, power and coordinates.
| Date and time | Satellite | FRP (MW) | Lat | Lon |
|---|
Other fires nearby
- 28,586 haLi20 March 2026 · 24 days · 9 km away
- 20,120 haLi23 March 2026 · 33 days · 19 km away
- 21,139 haSam Ngao6 February 2019 · 33 days · 20 km away
- 12,196 haSam Ngao1 March 2024 · 19 days · 20 km away
- 45,311 haSam Ngao21 March 2026 · 35 days · 22 km away
- 18,226 haSam Ngao13 March 2025 · 19 days · 27 km away
Frequently asked questions
- How long did the Li fire last?
- GWIS (Copernicus) dates it between 20 February 2023 and 23 February 2023: 4 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 1,269 hectares (12.7 km²). It is an estimate: official national figures may differ.
- Which municipalities burned?
- The fire only entered Li (1,275 ha, 0.7 %).
- What was the weather like?
- During the fire the temperature reached 32.5 °C, humidity dropped to 36 % and gusts hit 35 km/h. The fire danger index (FWI) reached 22, 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.