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Phrao fire, March 2023 พร้าว · Phrao

Out · last detection 6 Apr 2023, 18:56 UTC

The fire started on 30 March 2023 in Phrao, Thailand, and satellites saw it burning for 7 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 1,530 hectares from heat detections, spread across a single municipality.

It is the 201th largest in Chiang Mai Province since 2016 (of 399 with a page). Number 182 in Thailand in 2023, of 370.

Compare with…

Suggestions: Phrao · 2019Wiang Pa Pao · 2026Phrao · 2026Mae Suai · 2026

Burnt area
1,530ha
GWIS perimeter (Copernicus)
Duration
7days
30 Mar 2023 – 5 Apr 2023
Municipalities hit
1
districts
Started on
30 Mar
2023
Heat detections
39
in a single hotspot: 75 MW
Danger at start
30
High · FWI index
Average daily power
11MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 30 Mar5 Apr
6 Apr 2023

How it evolved, day by day

30 Mar 2023 · 11 MW · 3 31 Mar 2023 · 12 MW · 4 1 Apr 2023 · 26 MW · 9 2 Apr 2023 · 3 MW · 1 3 Apr 2023 · 6 MW · 3 5 Apr 2023 · 19 MW · 5 6 Apr 2023 · 1 MW · 1
30 Mar 31 Mar 1 Apr 2 Apr 3 Apr 5 Apr 6 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

34°high
45km/h · peak gust
25%lowest humidity

It had gone 13 days without rain (1 mm or more) when it started.

This area had burned before

90% of the perimeter overlaps earlier fires recorded since 2016: 501 ha in 2016, 314 ha in 2017, 402 ha in 2018, 829 ha in 2019, 1,214 ha in 2020, 95 ha in 2021. Part of it burned more than once, so the yearly figures add up to more than the 1,381 ha that had burned before.

How big is it?

10 km
It burned the equivalent of 1% of the area of London (15 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. Phrao พร้าว where it started
    1,540 ha
    1.2 %

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)
30 Mar 33.6 °C 27 % 34 km/h 0.0 mm High 30
31 Mar 33.2 °C 31 % 33 km/h 0.0 mm High 30
1 Apr 33.2 °C 33 % 38 km/h 0.0 mm High 32
2 Apr 33.5 °C 28 % 45 km/h 0.0 mm High 34
3 Apr 32.4 °C 31 % 43 km/h 0.0 mm High 33
4 Apr 33.1 °C 28 % 37 km/h 0.0 mm High 33
5 Apr 33.8 °C 25 % 27 km/h 0.0 mm High 30
6 Apr after 34.0 °C 29 % 20 km/h 0.0 mm High 29
7 Apr after 34.7 °C 31 % 29 km/h 0.0 mm High 32
8 Apr after 33.9 °C 34 % 29 km/h 0.0 mm High 32
9 Apr after 36.3 °C 28 % 33 km/h 0.0 mm High 34
10 Apr after 36.4 °C 29 % 29 km/h 0.0 mm High 32
11 Apr after 36.2 °C 30 % 27 km/h 0.0 mm High 33
12 Apr after 35.9 °C 30 % 28 km/h 0.0 mm High 33
13 Apr after 35.9 °C 33 % 32 km/h 0.0 mm High 34
14 Apr after 37.4 °C 28 % 26 km/h 0.0 mm High 34
15 Apr after 37.6 °C 25 % 23 km/h 0.0 mm High 34

Before and after, from space

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

Before · 23 Mar 2023
After · 12 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 30 March 2023 the air beside the fire reached 122 µg/m³ of PM2.5. That day averaged 61: 4.0 times the WHO daily guideline (15).

PM2.5 peak122 µg/m³
Days over the guideline12 days
PM10174 µg/m³
Optical depth1.59
2829303112345678
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 · 39Every 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 Phrao fire last?
GWIS (Copernicus) dates it between 30 March 2023 and 5 April 2023: 7 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 1,530 hectares (15.3 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire only entered Phrao (1,540 ha, 1.2 %).
What was the weather like?
During the fire the temperature reached 33.8 °C, humidity dropped to 25 % and gusts hit 45 km/h. The fire danger index (FWI) reached 34, 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. 39 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.