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Fang fire, March 2023 ฝาง · Fang

Out · last detection 1 Apr 2023, 18:50 UTC

The fire started on 24 March 2023 in Fang, Thailand, and satellites saw it burning for 9 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 3,008 hectares from heat detections, spread across a single municipality.

It is the 69th largest in Chiang Mai Province since 2016 (of 399 with a page). Number 53 in Thailand in 2023, of 370.

The power measured by the satellite is low (28.8 MW in the strongest hotspot), more typical of grass or stubble burning, or a slow surface fire, than of a large crown fire.

Compare with…

Suggestions: Mongton · 2026Mongton · 2020

Burnt area
3,008ha
GWIS perimeter (Copernicus)
Duration
9days
24 Mar 2023 – 1 Apr 2023
Municipalities hit
1
districts
Started on
24 Mar
2023
Heat detections
103
in a single hotspot: 29 MW
Danger at start
25
High · FWI index
Average daily power
31MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 24 Mar1 Apr
1 Apr 2023

How it evolved, day by day

24 Mar 2023 · 1 MW · 1 25 Mar 2023 · 4 MW · 2 26 Mar 2023 · 75 MW · 14 27 Mar 2023 · 19 MW · 2 28 Mar 2023 · 20 MW · 9 29 Mar 2023 · 12 MW · 7 30 Mar 2023 · 43 MW · 19 31 Mar 2023 · 46 MW · 16 1 Apr 2023 · 56 MW · 23
24 Mar 26 Mar 28 Mar 30 Mar 1 Apr

Fire radiative power detected each day, in megawatts, and number of hotspots. The magenta bar marks the peak day.

The weather it burned in

36°high
45km/h · peak gust
22%lowest humidity

It had gone 0 days without rain (1 mm or more) when it started.

This area had burned before

50% of the perimeter overlaps earlier fires recorded since 2016: 181 ha in 2016, 18 ha in 2017, 629 ha in 2019, 1,098 ha in 2020. Part of it burned more than once, so the yearly figures add up to more than the 1,504 ha that had burned before.

How big is it?

10 km
It burned the equivalent of 1.9% of the area of London (30 km² against 1,583 km²).

London boundary: geoBoundaries · Office for National Statistics (Open Government Licence v3.0).

This compares size, not location: both shapes are at the same scale, north up, centred on each other.

What happened to each town

  1. Fang ฝาง where it started
    3,026 ha
    3.7 %

Burnt area inside each municipality, from crossing the GWIS perimeter with administrative boundaries. The distance runs from the point marking the centre of each area 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)
22 Mar 33.9 °C 26 % 45 km/h 0.1 mm High 25
23 Mar 33.9 °C 24 % 37 km/h 0.0 mm High 25
24 Mar 33.2 °C 30 % 28 km/h 0.0 mm High 24
25 Mar 32.9 °C 29 % 28 km/h 0.0 mm High 24
26 Mar 34.2 °C 25 % 26 km/h 0.0 mm High 25
27 Mar 33.8 °C 30 % 26 km/h 0.0 mm High 27
28 Mar 35.6 °C 22 % 36 km/h 0.0 mm High 30
29 Mar 33.7 °C 26 % 36 km/h 0.0 mm High 31
30 Mar 34.6 °C 25 % 28 km/h 0.0 mm High 30
31 Mar 35.0 °C 25 % 30 km/h 0.0 mm High 31
1 Apr 35.7 °C 26 % 34 km/h 0.0 mm High 32
2 Apr after 34.1 °C 29 % 40 km/h 0.0 mm High 34
3 Apr after 34.0 °C 28 % 37 km/h 0.0 mm High 33
4 Apr after 34.9 °C 23 % 36 km/h 0.0 mm High 34
5 Apr after 35.4 °C 20 % 24 km/h 0.0 mm High 32
6 Apr after 35.7 °C 25 % 20 km/h 0.0 mm High 32
7 Apr after 36.6 °C 27 % 20 km/h 0.0 mm High 33
8 Apr after 37.0 °C 28 % 23 km/h 0.0 mm High 35
9 Apr after 38.4 °C 23 % 27 km/h 0.0 mm High 35
10 Apr after 38.2 °C 21 % 24 km/h 0.0 mm High 35
11 Apr after 37.1 °C 27 % 27 km/h 0.0 mm High 36

Before and after, from space

Drag the line to compare the same ground before the fire and after it.

Before · 17 Mar 2023
After · 8 Apr 2023

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 · Copernicus

On 27 March 2023 the air beside the fire reached 119 µg/m³ of PM2.5. That day averaged 57: 3.8 times the WHO daily guideline (15).

PM2.5 peak119 µg/m³
Days over the guideline14 days
PM10171 µg/m³
Optical depth1.16
222324252627282930311234
Good Fair Moderate Poor Very poor Extremely poor

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 · 103Every satellite heat detection, one by one, with time, satellite, power and coordinates.
⬇ Download CSV Times in UTC. Each detection is a 375 m pixel: a large fire yields hundreds per pass.
Date and timeSatelliteFRP (MW)LatLon

Other fires nearby

All fires in Thailand ›

Frequently asked questions

How long did the Fang fire last?
GWIS (Copernicus) dates it between 24 March 2023 and 1 April 2023: 9 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 3,008 hectares (30.1 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire only entered Fang (3,026 ha, 3.7 %).
What was the weather like?
During the fire the temperature reached 35.7 °C, humidity dropped to 22 % and gusts hit 45 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 · Emergency number and official warnings ›

Satellite cross-check

History of this page Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.

No changes since 24 October 2026.

RSS Changes to this page

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
What do you think is wrong?

We will only use your email to reply about this report. Privacy. This is not an emergency service: if there is a fire now, call 199 · 191.

How we know this
  • Perimeter: GWIS (Copernicus), rebuilt from heat detections rather than mapped on imagery.
  • Dates from the perimeter: the VIIRS detections inside it did not change them. 103 Suomi-NPP VIIRS detections on those dates.
  • We have not matched this page with any official record.
  • Weather: Copernicus ERA5 reanalysis at the fire location, in cells of about 25 km.

How we build fire pages: methodology ›

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.