Phrao fire, 23 March 2026 Chiang Dao, Chai Prakan, Phrao
The fire started on 23 March 2026 in Phrao, Thailand, and satellites saw it burning for 12 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 10,659 hectares from heat detections, spread across 3 municipalities.
It is the 11th largest in Chiang Mai Province since 2016 (of 463 with a page). Number 72 in Thailand in 2026, of 880.
The power measured by the satellite is low (28.0 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
- 10,659ha
- GWIS perimeter (Copernicus)
- Duration
- 12days
- 23 Mar 2026 – 3 Apr 2026
- Municipalities hit
- 3
- districts
- Started on
- 23 Mar
- 2026
- Heat detections
- 230
- in a single hotspot: 28 MW
- Danger at start
- 18
- Moderate · FWI index
- Energy released
- 827MW
- 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 3 days without rain (1 mm or more) when it started.
This area had burned before
89% of the perimeter overlaps earlier fires recorded since 2016: 3,760 ha in 2016, 2,857 ha in 2017, 594 ha in 2018, 1,290 ha in 2019, 6,212 ha in 2020, 2,185 ha in 2021, 211 ha in 2022, 1,007 ha in 2023, 2,505 ha in 2024, 1,906 ha in 2025. Part of it burned more than once, so the yearly figures add up to more than the 9,478 ha that had burned before.
- 1,117 ha Chiang Dao fire, March 2016 1,954 ha in total; the hectares shown are those it shares with this fire
- 1,014 ha Chiang Dao fire, March 2020 1,825 ha in total; the hectares shown are those it shares with this fire
- 729 ha Chai Prakan fire, March 2020 2,101 ha in total; the hectares shown are those it shares with this fire
- 622 ha Phrao fire, March 2024 1,294 ha in total; the hectares shown are those it shares with this fire
- 569 ha Chai Prakan fire, March 2017 1,046 ha in total; the hectares shown are those it shares with this fire
- 531 ha Chiang Dao fire, March 2021 1,175 ha in total; the hectares shown are those it shares with this fire
- 493 ha Chai Prakan fire, February 2020 1,437 ha in total; the hectares shown are those it shares with this fire
- 369 ha Phrao fire, March 2016 1,021 ha in total; the hectares shown are those it shares with this fire
What happened to each town
-
5,212 ha reached on 22 Mar2.4 %
-
3,660 ha reached on 23 Mar6.9 %
-
Phrao where it started1,846 ha reached on 20 Mar1.4 %
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 Mar | 33.2 °C | 32 % | 22 km/h | 0.0 mm | Moderate 18 |
| 21 Mar | 34.1 °C | 33 % | 35 km/h | 0.0 mm | Moderate 21 |
| 22 Mar | 33.9 °C | 30 % | 41 km/h | 0.2 mm | High 22 |
| 23 Mar | 34.5 °C | 28 % | 32 km/h | 0.0 mm | High 22 |
| 24 Mar | 34.9 °C | 24 % | 30 km/h | 0.0 mm | High 24 |
| 25 Mar | 35.0 °C | 23 % | 30 km/h | 0.0 mm | High 25 |
| 26 Mar | 35.6 °C | 26 % | 24 km/h | 0.0 mm | High 24 |
| 27 Mar | 36.1 °C | 26 % | 31 km/h | 0.0 mm | High 27 |
| 28 Mar | 36.5 °C | 22 % | 39 km/h | 0.0 mm | High 30 |
| 29 Mar | 36.7 °C | 19 % | 45 km/h | 0.0 mm | High 33 |
| 30 Mar | 36.0 °C | 26 % | 35 km/h | 0.0 mm | High 32 |
| 31 Mar | 36.7 °C | 27 % | 29 km/h | 0.0 mm | High 32 |
| 1 Apr | 35.9 °C | 31 % | 30 km/h | 0.0 mm | High 31 |
| 2 Apr | 36.9 °C | 27 % | 31 km/h | 0.0 mm | High 31 |
| 3 Apr | 37.9 °C | 24 % | 23 km/h | 0.0 mm | High 31 |
| 4 Apr after | 36.4 °C | 32 % | 27 km/h | 0.0 mm | High 31 |
| 5 Apr after | 36.8 °C | 33 % | 27 km/h | 0.0 mm | High 32 |
| 6 Apr after | 35.8 °C | 35 % | 24 km/h | 0.0 mm | High 29 |
| 7 Apr after | 35.8 °C | 36 % | 33 km/h | 0.0 mm | High 31 |
| 8 Apr after | 36.2 °C | 30 % | 34 km/h | 0.0 mm | High 32 |
| 9 Apr after | 35.6 °C | 29 % | 34 km/h | 0.0 mm | High 32 |
| 10 Apr after | 36.1 °C | 26 % | 40 km/h | 0.0 mm | High 35 |
| 11 Apr after | 36.6 °C | 24 % | 37 km/h | 0.0 mm | High 35 |
| 12 Apr after | 37.1 °C | 22 % | 26 km/h | 0.0 mm | High 35 |
| 13 Apr after | 37.4 °C | 26 % | 27 km/h | 0.0 mm | High 35 |
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 5 April 2026 the air beside the fire reached 102 µg/m³ of PM2.5. That day averaged 71: 4.8 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 · 230Every satellite heat detection, one by one, with time, satellite, power and coordinates.
| Date and time | Satellite | FRP (MW) | Lat | Lon |
|---|
Other fires nearby
- 12,293 haChai PrakanMarch 2026 · 32 days · 13 km away
- 14,912 haMae Suai28 March 2026 · 20 days · 29 km away
- 15,402 haPhrao26 March 2026 · 26 days · 32 km away
- 12,779 haWiang Pa Pao23 March 2026 · 28 days · 34 km away
- 10,618 haWiang Pa Pao4 April 2019 · 16 days · 34 km away
- 16,265 haPhrao17 March 2020 · 17 days · 38 km away
Frequently asked questions
- How long did the Phrao fire last?
- GWIS (Copernicus) dates it between 23 March 2026 and 3 April 2026: 12 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 10,659 hectares (106.6 km²). It is an estimate: official national figures may differ.
- Which municipalities burned?
- The fire entered 3 municipalities: Chiang Dao (5,212 ha, 2.4 %); Chai Prakan (3,660 ha, 6.9 %); Phrao (1,846 ha, 1.4 %).
- What was the weather like?
- During the fire the temperature reached 37.9 °C, humidity dropped to 19 % and gusts hit 45 km/h. The fire danger index (FWI) reached 33, 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.