How long did the Longtharai Valley fire last?

GWIS (Copernicus) dates it between 15 April 2026 and 22 April 2026: 8 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 6,636 hectares (66.4 km²). It is an estimate: official national figures may differ.

Which municipalities burned?

The fire entered 2 municipalities: Longtharai Valley (1,979 ha, 2.1 %); Kanchanpur (1,672 ha, 2.2 %).

What was the weather like?

During the fire the temperature reached 34.8 °C, humidity dropped to 37 % and gusts hit 55 km/h. The fire danger index (FWI) reached 17, class Moderate.

Where does this data come from?

From the GWIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of India (geoBoundaries). It is not an official report.

IN · India · 2026-04-15 → 2026-04-22

Longtharai Valley fire, 15 April 2026 Longtharai Valley, Kanchanpur

Out · last detection 22 Apr 2026, 07:24 UTC

The fire started on 15 April 2026 in Longtharai Valley, India, and satellites saw it burning for 8 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 6,636 hectares from heat detections, spread across 2 municipalities.

It is the 9th largest in Tripura since 2016 (of 13 with a page). Number 39 in India in 2026, of 65.

Burnt area: 6,636ha; GWIS perimeter (Copernicus)
Duration: 8days; 15 Apr 2026 – 22 Apr 2026
Municipalities hit: 2; subdistricts
Started on: 15 Apr; 2026
Heat detections: 111; in a single hotspot: 227 MW
Danger at start: 12; Moderate · FWI index
Energy released: 2.8GW; sum of detected power

Play back 22 Apr 2026

HOTSPOTS BY DAY 15 Apr22 Apr

How it evolved, day by day

151718202122

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

The weather it burned in

35°high

55km/h · peak gust

37%lowest humidity

It had gone one day without rain (1 mm or more) when it started. Rain came after the fire: 24.6 mm on 28 Apr.

This area had burned before

95% of the perimeter overlaps earlier fires recorded since 2016: 376 ha in 2016, 1,362 ha in 2017, 1,734 ha in 2018, 529 ha in 2019, 2,591 ha in 2020, 3,666 ha in 2021, 1,841 ha in 2022, 3,209 ha in 2023, 3,283 ha in 2024, 2,244 ha in 2025. Part of it burned more than once, so the yearly figures add up to more than the 6,305 ha that had burned before.

What happened to each town

Longtharai Valley where it started

1,979 ha reached on 13 Apr

2.1 %
Kanchanpur

1,672 ha reached on 15 Apr

2.2 %

Burnt area inside each municipality, from crossing the GWIS perimeter with administrative boundaries. The distance is from the town centre 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)
12 Apr	32.0 °C	37 %	43 km/h	0.0 mm	Moderate 12
13 Apr	33.2 °C	41 %	44 km/h	0.0 mm	Moderate 13
14 Apr	32.0 °C	55 %	38 km/h	0.3 mm	Moderate 11
15 Apr	33.3 °C	43 %	40 km/h	1.3 mm	Low 9
16 Apr	32.3 °C	49 %	28 km/h	0.2 mm	Low 10
17 Apr	34.2 °C	46 %	28 km/h	0.1 mm	Moderate 12
18 Apr	31.9 °C	56 %	27 km/h	1.5 mm	Very low 5
19 Apr	31.2 °C	62 %	34 km/h	2.1 mm	Very low 3
20 Apr	33.5 °C	52 %	48 km/h	0.6 mm	Low 11
21 Apr	32.7 °C	53 %	55 km/h	0.8 mm	Moderate 12
22 Apr	34.4 °C	47 %	49 km/h	0.6 mm	Moderate 15
23 Apr after	34.1 °C	44 %	23 km/h	0.0 mm	Moderate 14
24 Apr after	34.7 °C	45 %	26 km/h	0.1 mm	Moderate 15
25 Apr after	34.8 °C	41 %	30 km/h	0.1 mm	Moderate 17
26 Apr after	31.8 °C	48 %	34 km/h	0.4 mm	Moderate 17
27 Apr after	26.5 °C	65 %	62 km/h	0.3 mm	Moderate 16
28 Apr after	23.6 °C	86 %	47 km/h	24.6 mm	Very low 0

Before and after, from space

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

↔

Before · 8 Apr 2026

After · 29 Apr 2026

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 16 April 2026 the air beside the fire reached 96 µg/m³ of PM2.5. That day averaged 72: 4.8 times the WHO daily guideline (15).

PM2.5 peak96 µg/m³

Days over the guideline19 days

PM10118 µg/m³

Optical depth2.91

WHO 15

10111213141516171819202122232425262728

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 · 111Every 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 India ›

Frequently asked questions

How long did the Longtharai Valley fire last?: GWIS (Copernicus) dates it between 15 April 2026 and 22 April 2026: 8 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 6,636 hectares (66.4 km²). It is an estimate: official national figures may differ.
Which municipalities burned?: The fire entered 2 municipalities: Longtharai Valley (1,979 ha, 2.1 %); Kanchanpur (1,672 ha, 2.2 %).
What was the weather like?: During the fire the temperature reached 34.8 °C, humidity dropped to 37 % and gusts hit 55 km/h. The fire danger index (FWI) reached 17, class Moderate.
Where does this data come from?: From the GWIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of India (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: 112

Satellite cross-check

NASA FIRMS ↗
GWIS · Copernicus ↗

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 112.

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 ADM3 (Open Data Commons Open Database License 1.0). 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