How long did the Den Chai fire last?

According to the heat detections seen by satellite inside the perimeter, it burned from 4 March 2019 to 22 March 2019 (19 days). The perimeter dates it from 7 March 2019 to 15 March 2019.

How much area did it burn?

The perimeter GWIS (Copernicus) rebuilt from heat detections is 4,107 hectares (41.1 km²). It is an estimate: official national figures may differ.

Which municipalities burned?

The fire entered 4 municipalities: Den Chai (2,104 ha, 3.8 %); Mueang Uttaradit (1,582 ha, 2.0 %); Tha Pla (410 ha, 0.2 %); Sung Men (35 ha, 0.1 %).

What was the weather like?

During the fire the temperature reached 33.9 °C, humidity dropped to 21 % and gusts hit 40 km/h. The fire danger index (FWI) reached 31, 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.

TH · Thailand · 2019-03-04 → 2019-03-22

Den Chai fire, March 2019 เด่นชัย · Den Chai, Mueang Uttaradit, Tha Pla

Out · last detection 20 Mar 2019, 06:35 UTC

The fire started on 4 March 2019 in Den Chai, Thailand, and satellites saw it burning for 19 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 4,107 hectares from heat detections, spread across 4 municipalities.

It is the 7th largest in Phrae Province since 2016 (of 116 with a page). Number 29 in Thailand in 2019, of 386.

The power measured by the satellite is low (15.2 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: Den Chai · 2016 Mueang Phrae · 2023

Burnt area: 4,107ha; GWIS perimeter (Copernicus)
Duration: 19days; 4 Mar 2019 – 22 Mar 2019
Municipalities hit: 4; districts
Started on: 4 Mar; 2019
Heat detections: 137; in a single hotspot: 15 MW
Danger at start: 25; High · FWI index
Average daily power: 37MW; detected power per day, on average

HOTSPOTS BY DAY 4 Mar22 Mar

Play back 20 Mar 2019

How it evolved, day by day

4 Mar 8 Mar 10 Mar 12 Mar 14 Mar 16 Mar 20 Mar

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

40km/h · peak gust

21%lowest humidity

It had gone 14 days without rain (1 mm or more) when it started.

This area had burned before

69% of the perimeter overlaps earlier fires recorded since 2016: 3,316 ha in 2016, 79 ha in 2017, 716 ha in 2018. Part of it burned more than once, so the yearly figures add up to more than the 2,823 ha that had burned before.

1,310 ha Den Chai fire, March 2016 6,208 ha in total; the hectares shown are those it shares with this fire

How big is it?

It burned the equivalent of 2.6% of the area of London (41 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

Den Chai เด่นชัย where it started

2,104 ha reached on 4 Mar

3.8 %
Mueang Uttaradit เมืองอุตรดิตถ์

1,582 ha reached on 8 Mar

2.0 %
Tha Pla ท่าปลา

410 ha reached on 9 Mar

0.2 %
Sung Men สูงเม่น

35 ha

0.1 %

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.

People and buildings inside the perimeter

GHSL 2020

Built-up area0.44 ha

Residents≈ 50

Inside the perimeter there were about 0.44 hectares of built-up land and about 50 residents (GHSL 2020, satellite-based estimate).

This is an estimate on 100 m cells, made from satellite imagery and census data: it does not mean that homes burned or that anyone was harmed. The perimeter also contains land that never burned.

Source: Global Human Settlement Layer (GHS-BUILT-S and GHS-POP R2023A), European Commission Joint Research Centre (JRC), © European Union, CC BY 4.0. Sum inside the perimeter computed by WorldFires. human-settlement.emergency.copernicus.eu

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)
4 Mar	33.3 °C	29 %	36 km/h	0.0 mm	High 25
5 Mar	33.2 °C	26 %	35 km/h	0.0 mm	High 26
6 Mar	33.3 °C	24 %	33 km/h	0.0 mm	High 26
7 Mar	33.7 °C	28 %	30 km/h	0.0 mm	High 26
8 Mar	33.5 °C	31 %	39 km/h	0.0 mm	High 30
9 Mar	33.9 °C	30 %	40 km/h	0.0 mm	High 31
10 Mar	33.5 °C	26 %	30 km/h	0.0 mm	High 28
11 Mar	33.4 °C	21 %	29 km/h	0.0 mm	High 28
12 Mar	33.2 °C	27 %	30 km/h	0.0 mm	High 30
13 Mar	33.1 °C	29 %	29 km/h	0.0 mm	High 30
14 Mar	32.8 °C	35 %	27 km/h	0.0 mm	High 27
15 Mar	33.4 °C	34 %	26 km/h	0.0 mm	High 27
16 Mar	33.3 °C	39 %	30 km/h	0.0 mm	High 26
17 Mar	33.9 °C	40 %	30 km/h	0.0 mm	High 26
18 Mar	34.1 °C	38 %	30 km/h	0.4 mm	High 26
19 Mar	34.3 °C	35 %	35 km/h	0.0 mm	High 28
20 Mar	34.8 °C	30 %	34 km/h	0.0 mm	High 30
21 Mar	36.0 °C	25 %	26 km/h	0.0 mm	High 31
22 Mar	35.9 °C	24 %	25 km/h	0.0 mm	High 31
23 Mar after	35.6 °C	27 %	24 km/h	0.0 mm	High 32
24 Mar after	35.9 °C	27 %	31 km/h	0.0 mm	High 34
25 Mar after	33.9 °C	41 %	33 km/h	0.4 mm	High 29

Before and after, from space

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

↔

Before · 25 Feb 2019

After · 29 Mar 2019

Before After

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 · 137Every 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 time	Satellite	FRP (MW)	Lat	Lon

Other fires nearby

All fires in Thailand ›

Frequently asked questions

How long did the Den Chai fire last?: According to the heat detections seen by satellite inside the perimeter, it burned from 4 March 2019 to 22 March 2019 (19 days). The perimeter dates it from 7 March 2019 to 15 March 2019.
How much area did it burn?: The perimeter GWIS (Copernicus) rebuilt from heat detections is 4,107 hectares (41.1 km²). It is an estimate: official national figures may differ.
Which municipalities burned?: The fire entered 4 municipalities: Den Chai (2,104 ha, 3.8 %); Mueang Uttaradit (1,582 ha, 2.0 %); Tha Pla (410 ha, 0.2 %); Sung Men (35 ha, 0.1 %).
What was the weather like?: During the fire the temperature reached 33.9 °C, humidity dropped to 21 % and gusts hit 40 km/h. The fire danger index (FWI) reached 31, 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

NASA FIRMS ↗
GWIS · Copernicus ↗

History of this page · 2 Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.

26 October 2026 Last day with fire: 15 March 2019 → 22 March 2019.
26 October 2026 Start date: 7 March 2019 → 4 March 2019.

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?

Dates or duration Place or towns Burned area Name It was not a wildfire Same fire as another page Something else

What really happened?

Your connection to the fire (optional) Email (optional)

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 adjusted with the VIIRS detections inside the perimeter, which said 7 March 2019 to 15 March 2019. 137 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.
Built-up area and population come from the JRC Global Human Settlement Layer (epoch 2020, 100 m cells), summed inside the perimeter: an estimate of what was there, not a damage count.

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.

Where it burned