Ambassa fire, April 2023 Ambassa, Longtharai Valley
The fire started on 5 April 2023 in Ambassa, India, and satellites saw it burning for 11 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 8,538 hectares from heat detections, spread across 2 municipalities.
It is the 8th largest in Tripura since 2016 (of 13 with a page). Number 10 in India in 2023, of 22.
Compare with…
We have the GWIS perimeter for this fire, but the VIIRS sensors did not capture it in enough detail: no day-by-day evolution, but the split by municipality is there.
- Burnt area
- 8,538ha
- GWIS perimeter (Copernicus)
- Duration
- 11days
- 5 Apr 2023 – 15 Apr 2023
- Municipalities hit
- 2
- subdistricts
- Started on
- 5 Apr
- 2023
- Danger at start
- 0
- Very low · FWI index
Where it burned
The weather it burned in
It had gone one day without rain (1 mm or more) when it started. Rain came after the fire: 3.4 mm on 17 Apr.
This area had burned before
93% of the perimeter overlaps earlier fires recorded since 2016: 3,172 ha in 2016, 3,735 ha in 2017, 4,499 ha in 2018, 2,569 ha in 2019, 3,457 ha in 2020, 6,205 ha in 2021, 1,904 ha in 2022. Part of it burned more than once, so the yearly figures add up to more than the 7,899 ha that had burned before.
How big is it?
London boundary: geoBoundaries · Office for National Statistics (Open Government Licence v3.0).
Paris boundary: geoBoundaries · Institut national de l'information géographique et forestière (IGN-F) (Etalab Open License 2.0).
Madrid boundary: geoBoundaries · Open Data ESRI, IGN Central Registry of Cartography Area (CC BY 4.0).
Berlin boundary: geoBoundaries · Federal Agency for Cartography and Geodesy (dl-de/by-2-0).
This compares size, not location: both shapes are at the same scale, north up, centred on each other.
What happened to each town
-
Ambassa where it started7,242 ha13 %
-
1,333 ha1.4 %
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 2025Inside the perimeter there were about 23 hectares of built-up land and about 3,600 residents (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) |
|---|---|---|---|---|---|
| 5 Apr | 30.9 °C | 59 % | 49 km/h | 12.0 mm | Very low 0 |
| 6 Apr | 33.2 °C | 41 % | 20 km/h | 0.2 mm | Very low 3 |
| 7 Apr | 35.5 °C | 28 % | 22 km/h | 0.0 mm | Low 10 |
| 8 Apr | 36.0 °C | 23 % | 27 km/h | 0.0 mm | Moderate 14 |
| 9 Apr | 36.8 °C | 26 % | 29 km/h | 0.0 mm | Moderate 16 |
| 10 Apr | 36.9 °C | 28 % | 29 km/h | 0.0 mm | Moderate 17 |
| 11 Apr | 36.8 °C | 29 % | 27 km/h | 0.0 mm | Moderate 18 |
| 12 Apr | 37.9 °C | 24 % | 26 km/h | 0.0 mm | Moderate 19 |
| 13 Apr | 38.0 °C | 27 % | 26 km/h | 0.0 mm | High 22 |
| 14 Apr | 38.9 °C | 25 % | 28 km/h | 0.0 mm | High 22 |
| 15 Apr | 38.6 °C | 30 % | 30 km/h | 0.0 mm | High 24 |
| 16 Apr after | 38.8 °C | 31 % | 36 km/h | 0.0 mm | High 27 |
| 17 Apr after | 37.4 °C | 42 % | 33 km/h | 3.4 mm | Low 8 |
Before and after, from space
Drag the line to compare the same ground before the fire and after it.
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 · CopernicusOn 12 April 2023 the air beside the fire reached 637 µg/m³ of PM2.5. That day averaged 251: 17 times the WHO daily guideline (15).
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)
Other fires nearby
- 15,588 haAmbassaApril 2026 · 12 days · 7 km away
- 24,186 haGandacherraMarch 2020 · 12 days · 16 km away
- 21,363 haLongtharai ValleyApril 2023 · 14 days · 16 km away
- 10,443 haLongtharai Valley25 March 2020 · 8 days · 18 km away
- 15,481 haLongtharai ValleyMarch 2021 · 10 days · 25 km away
- 15,041 haGandacherraApril 2026 · 12 days · 29 km away
Frequently asked questions
- How long did the Ambassa fire last?
- GWIS (Copernicus) dates it between 5 April 2023 and 15 April 2023: 11 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 8,538 hectares (85.4 km²). It is an estimate: official national figures may differ.
- Which municipalities burned?
- The fire entered 2 municipalities: Ambassa (7,242 ha, 13 %); Longtharai Valley (1,333 ha, 1.4 %).
- What was the weather like?
- During the fire the temperature reached 38.9 °C, humidity dropped to 23 % and gusts hit 49 km/h. The fire danger index (FWI) reached 24, class High.
- 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 · 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.
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
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. No 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.
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.