How long did the Na Noi fire last?

According to the heat detections seen by satellite inside the perimeter, it burned from 20 March 2023 to 30 March 2023 (11 days). The perimeter dates it from 20 March 2023 to 26 March 2023.

How much area did it burn?

The perimeter GWIS (Copernicus) rebuilt from heat detections is 1,233 hectares (12.3 km²). It is an estimate: official national figures may differ.

Which municipalities burned?

The fire only entered Na Noi (1,240 ha, 1.0 %).

What was the weather like?

During the fire the temperature reached 37.0 °C, humidity dropped to 25 % and gusts hit 47 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.

TH · Thailand · 2023-03-20 → 2023-03-30

Na Noi fire, 20 March 2023 นาน้อย · Na Noi

Out · last detection 27 Mar 2023, 18:44 UTC

The fire started on 20 March 2023 in Na Noi, Thailand, and satellites saw it burning for 11 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 1,233 hectares from heat detections, spread across a single municipality.

It is the 127th largest in Nan Province since 2016 (of 189 with a page). Number 260 in Thailand in 2023, of 369.

The power measured by the satellite is low (16.6 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: Na Noi · 2016 Song · 2026 Wiang Sa · 2026 Na Muen · 2026

Burnt area: 1,233ha; GWIS perimeter (Copernicus)
Duration: 11days; 20 Mar 2023 – 30 Mar 2023
Municipalities hit: 1; districts
Started on: 20 Mar; 2023
Heat detections: 40; in a single hotspot: 17 MW
Danger at start: 26; High · FWI index
Average daily power: 25MW; detected power per day, on average

HOTSPOTS BY DAY 20 Mar30 Mar

Play back 27 Mar 2023

How it evolved, day by day

20 Mar 22 Mar 23 Mar 24 Mar 25 Mar 26 Mar 27 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

37°high

47km/h · peak gust

25%lowest humidity

It had gone 3 days without rain (1 mm or more) when it started.

This area had burned before

81% of the perimeter overlaps earlier fires recorded since 2016: 527 ha in 2016, 430 ha in 2017, 217 ha in 2018, 563 ha in 2019. Part of it burned more than once, so the yearly figures add up to more than the 1,003 ha that had burned before.

527 ha Na Noi fire, March 2016 1,911 ha in total; the hectares shown are those it shares with this fire

How big is it?

It burned the equivalent of 0.8% of the area of London (12 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

Na Noi นาน้อย where it started

1,240 ha reached on 20 Mar

1.0 %

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 area0.20 ha

Residents< 20

Inside the perimeter there were about 0.20 hectares of 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)
20 Mar	35.4 °C	34 %	35 km/h	0.0 mm	High 26
21 Mar	35.6 °C	30 %	40 km/h	0.1 mm	High 30
22 Mar	36.1 °C	28 %	43 km/h	0.0 mm	High 33
23 Mar	36.9 °C	25 %	47 km/h	0.1 mm	High 36
24 Mar	37.0 °C	26 %	37 km/h	0.0 mm	High 34
25 Mar	36.5 °C	25 %	40 km/h	0.0 mm	High 35
26 Mar	35.8 °C	30 %	40 km/h	0.0 mm	High 36
27 Mar	36.7 °C	26 %	38 km/h	0.0 mm	High 36
28 Mar	35.6 °C	35 %	40 km/h	0.0 mm	High 35
29 Mar	35.6 °C	33 %	42 km/h	0.0 mm	High 35
30 Mar	34.7 °C	34 %	33 km/h	0.0 mm	High 33
31 Mar after	35.4 °C	34 %	33 km/h	0.0 mm	High 33
1 Apr after	35.2 °C	37 %	36 km/h	0.0 mm	High 33
2 Apr after	36.3 °C	28 %	43 km/h	0.0 mm	High 35
3 Apr after	36.4 °C	25 %	41 km/h	0.0 mm	High 38
4 Apr after	36.3 °C	27 %	40 km/h	0.0 mm	High 37
5 Apr after	36.3 °C	26 %	31 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.

↔

Before · 13 Mar 2023

After · 6 Apr 2023

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.

The smoke

CAMS · Copernicus

On 25 March 2023 the air beside the fire reached 48 µg/m³ of PM2.5. That day averaged 33: 2.2 times the WHO daily guideline (15).

PM2.5 peak48 µg/m³

Days over the guideline12 days

PM1070 µg/m³

Optical depth1.08

WHO 15

181920212223242526272829

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 · 40Every 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 Na Noi fire last?: According to the heat detections seen by satellite inside the perimeter, it burned from 20 March 2023 to 30 March 2023 (11 days). The perimeter dates it from 20 March 2023 to 26 March 2023.
How much area did it burn?: The perimeter GWIS (Copernicus) rebuilt from heat detections is 1,233 hectares (12.3 km²). It is an estimate: official national figures may differ.
Which municipalities burned?: The fire only entered Na Noi (1,240 ha, 1.0 %).
What was the weather like?: During the fire the temperature reached 37.0 °C, humidity dropped to 25 % and gusts hit 47 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.

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 · 1 Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.

26 October 2026 Last day with fire: 26 March 2023 → 30 March 2023.

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.

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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 20 March 2023 to 26 March 2023. 40 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.

Where it burned