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Na Noi fire, 24 March 2023 นาน้อย · Na Noi

Out · last detection 10 Apr 2023, 06:51 UTC

The fire started on 24 March 2023 in Na Noi, Thailand, and satellites saw it burning for 17 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 1,600 hectares from heat detections, spread across a single municipality.

It is the 65th largest in Nan Province since 2016 (of 157 with a page). Number 165 in Thailand in 2023, of 369.

Compare with…

Suggestions: Na Noi · 2025Pong · 2016Na Noi · 2020Na Noi · 2019

Burnt area
1,600ha
GWIS perimeter (Copernicus)
Duration
17days
24 Mar 2023 – 9 Apr 2023
Municipalities hit
1
districts
Started on
24 Mar
2023
Heat detections
61
in a single hotspot: 76 MW
Danger at start
33
High · FWI index
Average daily power
29MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 24 Mar9 Apr
10 Apr 2023

How it evolved, day by day

25 Mar 2023 · 22 MW · 7 26 Mar 2023 · 44 MW · 17 27 Mar 2023 · 224 MW · 25 29 Mar 2023 · 3 MW · 2 30 Mar 2023 · 7 MW · 2 31 Mar 2023 · 3 MW · 3 1 Apr 2023 · 8 MW · 1 2 Apr 2023 · 1 MW · 1 4 Apr 2023 · 3 MW · 1 6 Apr 2023 · 1 MW · 1 10 Apr 2023 · 2 MW · 1
27 Mar 1 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
43km/h · peak gust
24%lowest humidity

It had gone 7 days without rain (1 mm or more) when it started.

This area had burned before

96% of the perimeter overlaps earlier fires recorded since 2016: 693 ha in 2016, 108 ha in 2017, 1,165 ha in 2019, 774 ha in 2020. Part of it burned more than once, so the yearly figures add up to more than the 1,542 ha that had burned before.

How big is it?

10 km
It burned the equivalent of 1% of the area of London (16 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. Na Noi นาน้อย where it started
    1,609 ha reached on 25 Mar
    1.3 %

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 2025
Built-up area< 0.1 ha
Residents< 20

Inside the perimeter there was no noticeable built-up land and almost nobody lived there (GHSL 2025, 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. The GHSL 2025 epoch is a projection made from 2020 and earlier data.

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)
24 Mar 33.9 °C 25 % 37 km/h 0.0 mm High 33
25 Mar 33.4 °C 24 % 40 km/h 0.0 mm High 34
26 Mar 32.8 °C 29 % 40 km/h 0.0 mm High 35
27 Mar 33.7 °C 25 % 38 km/h 0.0 mm High 35
28 Mar 32.5 °C 34 % 40 km/h 0.0 mm High 34
29 Mar 32.5 °C 32 % 42 km/h 0.0 mm High 34
30 Mar 31.7 °C 33 % 33 km/h 0.0 mm High 32
31 Mar 32.4 °C 33 % 33 km/h 0.0 mm High 32
1 Apr 32.1 °C 36 % 36 km/h 0.0 mm High 32
2 Apr 33.2 °C 27 % 43 km/h 0.0 mm High 34
3 Apr 33.4 °C 24 % 41 km/h 0.0 mm High 36
4 Apr 33.2 °C 26 % 40 km/h 0.0 mm High 36
5 Apr 33.3 °C 25 % 31 km/h 0.0 mm High 34
6 Apr 33.6 °C 29 % 28 km/h 0.0 mm High 33
7 Apr 34.0 °C 29 % 32 km/h 0.0 mm High 35
8 Apr 33.0 °C 38 % 31 km/h 0.2 mm High 31
9 Apr 32.4 °C 44 % 34 km/h 0.4 mm High 29
10 Apr after 34.5 °C 30 % 33 km/h 0.0 mm High 31
11 Apr after 34.8 °C 31 % 35 km/h 0.0 mm High 32
12 Apr after 35.2 °C 28 % 34 km/h 0.0 mm High 33
13 Apr after 34.6 °C 34 % 32 km/h 0.0 mm High 34
14 Apr after 35.9 °C 29 % 31 km/h 0.0 mm High 34
15 Apr after 35.4 °C 30 % 34 km/h 0.0 mm High 33
16 Apr after 33.2 °C 41 % 35 km/h 0.3 mm High 31
17 Apr after 34.8 °C 31 % 37 km/h 0.0 mm High 33
18 Apr after 35.6 °C 30 % 35 km/h 0.0 mm High 34
19 Apr after 35.2 °C 33 % 36 km/h 0.0 mm High 34

Its twins: fires that started in the same weather

It started with an FWI of 33.1, a minimum humidity of 25% and 7 days without rain. Fires in the area that started in weather like this since 2016: 20.

FWI at the start 33.1
Minimum humidity 25 %
Days without rain 7
this fire chosen twins rest of the area
Almost identicalSimilar

Outlines of the closest twins

Na Noi fire, March 2025
1,434 ha 4 days FWI 32.0 Min. humidity 26 % 38 km away, in 2025

First rain (1 mm or more) after it ended: none in the following ten days.

See its page Compare with this fire

What happened to them

9 days
median duration
1,419 ha
median area
100 %
went past 1,000 ha
1.4 mm
rain at the end (median; 12 of 20 had it)

It burned an area similar to its twins (1,600 ha against a median of 1,419 ha) and lasted 17 days, against 9 days.

In 8 of 20, not even 1 mm fell in the ten days after the end: they went out without rain. In the rest, the first rainy day brought a median of 1.4 mm.

This is a bank of analogues: it shows what usually happens, not what will happen. With fewer than 15 twins we give no figures. How we calculate it

How it ended

—first rain
—no rain in ten days
43km/h · max. gust

It was considered over on 9 Apr, and not even 1 mm fell in the following ten days: it went out without rain. Twins with rain when they ended: 12 of 20, with a median of 1.4 mm.

Weather on this page: Open-Meteo.com (CC BY 4.0) · Copernicus Climate Change Service (ERA5)

How a twin is chosen

  • Same area: fires that have already ended, less than 250 km from this one, since 2016.
  • Same start: we compare the FWI on the first day, the minimum humidity that day and the run of days without rain before it. The slider sets how much they may differ.
  • Only pages with final weather data (ERA5 reanalysis) calculated in the same way as this fire’s; agricultural and grass burns and pages with data under review are left out.
  • Fires burning at the same time as this one (a week before or after) are left out: they share the same spell of weather and do not count as a precedent.
  • They are sorted by similarity, and the outlines of the first five are drawn.

How we calculate it

Before and after, from space

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

Before · 17 Mar 2023
After · 16 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 31 March 2023 the air beside the fire reached 64 µg/m³ of PM2.5. That day averaged 46: 3.1 times the WHO daily guideline (15).

PM2.5 peak64 µg/m³
Days over the guideline14 days
PM1092 µg/m³
Optical depth1.23
23 Mar26 Mar29 Mar1 Apr4 Apr
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 · 61Every 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 Na Noi fire last?
According to the heat detections seen by satellite inside the perimeter, it burned from 24 March 2023 to 9 April 2023 (17 days). The perimeter dates it from 25 March 2023 to 2 April 2023.
How much area did it burn?
The perimeter GWIS (Copernicus) rebuilt from heat detections is 1,600 hectares (16.0 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire only entered Na Noi (1,609 ha, 1.3 %).
What was the weather like?
During the fire the temperature reached 34.0 °C, humidity dropped to 24 % and gusts hit 43 km/h. The fire danger index (FWI) reached 36, 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.
How did the fires that started in similar weather in this area end?
Fires less than 250 km away that started since 2016 with a similar FWI, humidity and dry spell: 20. Their median duration was 9 days and their median area 1,419 ha; 100 % went past 1,000 ha. In 8 of 20, not even 1 mm fell in the ten days after the end: they went out without rain. In the rest, the first rainy day brought a median of 1.4 mm.

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 · 2 Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.
  1. Last day with fire: 2 April 2023 → 9 April 2023.
  2. Start date: 25 March 2023 → 24 March 2023.

RSS Changes to this page With cross-checks and a citable version

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 adjusted with the VIIRS detections inside the perimeter, which said 25 March 2023 to 2 April 2023. 61 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 2025, 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.