Li fire, 15 March 2018 Li, Sam Ngao
The fire started on 15 March 2018 in Li, Thailand, and satellites saw it burning for 6 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 1,437 hectares from heat detections, spread across 2 municipalities.
It is the 254th largest in Chiang Mai Province since 2016 (of 463 with a page). Number 82 in Thailand in 2018, of 144.
The power measured by the satellite is low (13.6 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
- 1,437ha
- GWIS perimeter (Copernicus)
- Duration
- 6days
- 15 Mar 2018 – 20 Mar 2018
- Municipalities hit
- 2
- districts
- Started on
- 15 Mar
- 2018
- Heat detections
- 59
- in a single hotspot: 14 MW
- Danger at start
- 29
- High · FWI index
- Energy released
- 257MW
- 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 9 days without rain (1 mm or more) when it started.
This area had burned before
91% of the perimeter overlaps earlier fires recorded since 2016: 888 ha in 2016, 685 ha in 2017. Part of it burned more than once, so the yearly figures add up to more than the 1,305 ha that had burned before.
- 444 ha Li fire, March 2016 1,309 ha in total; the hectares shown are those it shares with this fire
- 338 ha Li fire, March 2017 1,254 ha in total; the hectares shown are those it shares with this fire
- 104 ha Sam Ngao fire, March 2017 1,183 ha in total; the hectares shown are those it shares with this fire
What happened to each town
-
Li where it started1,385 ha reached on 13 Mar0.8 %
-
57 ha reached on 19 Mar0.0 %
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) |
|---|---|---|---|---|---|
| 6 Mar | 34.9 °C | 24 % | 23 km/h | 0.0 mm | High 29 |
| 7 Mar | 35.4 °C | 22 % | 20 km/h | 0.0 mm | High 30 |
| 8 Mar | 33.5 °C | 31 % | 31 km/h | 0.0 mm | High 29 |
| 9 Mar | 26.4 °C | 68 % | 37 km/h | 2.6 mm | Very low 4 |
| 10 Mar | 29.0 °C | 49 % | 29 km/h | 0.4 mm | Low 9 |
| 11 Mar | 29.6 °C | 41 % | 23 km/h | 0.3 mm | Moderate 15 |
| 12 Mar | 30.3 °C | 43 % | 26 km/h | 0.1 mm | Moderate 16 |
| 13 Mar | 32.7 °C | 26 % | 22 km/h | 0.0 mm | High 23 |
| 14 Mar | 32.0 °C | 28 % | 30 km/h | 0.0 mm | High 26 |
| 15 Mar | 32.6 °C | 28 % | 27 km/h | 0.0 mm | High 25 |
| 16 Mar | 32.7 °C | 30 % | 23 km/h | 0.0 mm | High 26 |
| 17 Mar | 33.0 °C | 31 % | 28 km/h | 0.0 mm | High 26 |
| 18 Mar | 33.5 °C | 31 % | 31 km/h | 0.0 mm | High 27 |
| 19 Mar | 33.9 °C | 25 % | 28 km/h | 0.0 mm | High 29 |
| 20 Mar | 34.0 °C | 29 % | 25 km/h | 0.0 mm | High 29 |
| 21 Mar after | 33.8 °C | 26 % | 26 km/h | 0.0 mm | High 29 |
| 22 Mar after | 31.5 °C | 37 % | 36 km/h | 0.0 mm | High 29 |
| 23 Mar after | 28.9 °C | 51 % | 29 km/h | 0.5 mm | Moderate 21 |
| 24 Mar after | 31.4 °C | 42 % | 27 km/h | 0.1 mm | Moderate 20 |
| 25 Mar after | 31.6 °C | 43 % | 19 km/h | 0.1 mm | High 22 |
| 26 Mar after | 32.0 °C | 37 % | 19 km/h | 0.0 mm | High 23 |
| 27 Mar after | 31.9 °C | 35 % | 32 km/h | 0.0 mm | High 25 |
| 28 Mar after | 33.5 °C | 30 % | 29 km/h | 0.0 mm | High 28 |
| 29 Mar after | 32.8 °C | 36 % | 22 km/h | 0.0 mm | High 27 |
| 30 Mar after | 33.1 °C | 35 % | 22 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.
Detections table · 59Every satellite heat detection, one by one, with time, satellite, power and coordinates.
| Date and time | Satellite | FRP (MW) | Lat | Lon |
|---|
Other fires nearby
- 21,139 haSam Ngao6 February 2019 · 33 days · 20 km away
- 20,120 haLi23 March 2026 · 33 days · 21 km away
- 12,196 haSam Ngao1 March 2024 · 19 days · 22 km away
- 18,226 haSam Ngao13 March 2025 · 19 days · 23 km away
- 28,586 haLi20 March 2026 · 24 days · 25 km away
- 45,311 haSam Ngao21 March 2026 · 35 days · 26 km away
Frequently asked questions
- How long did the Li fire last?
- GWIS (Copernicus) dates it between 15 March 2018 and 20 March 2018: 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 1,437 hectares (14.4 km²). It is an estimate: official national figures may differ.
- Which municipalities burned?
- The fire entered 2 municipalities: Li (1,385 ha, 0.8 %); Sam Ngao (57 ha, 0.0 %).
- What was the weather like?
- During the fire the temperature reached 35.4 °C, humidity dropped to 22 % and gusts hit 37 km/h. The fire danger index (FWI) reached 30, 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.