Skip to content
worldfires
NP · Nepal · –

Rapti Sonari fire, 18 April 2019 Rapti Sonari, Babai

Out · last detection 30 Apr 2019, 19:36 UTC

The fire started on 18 April 2019 in Rapti Sonari, Nepal, and satellites saw it burning for 13 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 3,535 hectares from heat detections, spread across 2 municipalities.

It is the 19th largest in Lumbini since 2016 (of 47 with a page). Number 9 in Nepal in 2019, of 25.

The power measured by the satellite is low (8.4 MW in the strongest hotspot), more typical of grass or stubble burning, or a slow surface fire, than of a large crown fire.

Burnt area
3,535ha
GWIS perimeter (Copernicus)
Duration
13days
18 Apr 2019 – 30 Apr 2019
Municipalities hit
2
municipalities
Started on
18 Apr
2019
Heat detections
100
in a single hotspot: 8 MW
Danger at start
19
Moderate · FWI index
Average daily power
26MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 18 Apr30 Apr
30 Apr 2019

How it evolved, day by day

19 Apr 2019 · 12 MW · 6 20 Apr 2019 · 63 MW · 19 21 Apr 2019 · 61 MW · 20 22 Apr 2019 · 28 MW · 11 23 Apr 2019 · 23 MW · 12 24 Apr 2019 · 26 MW · 8 25 Apr 2019 · 5 MW · 1 26 Apr 2019 · 18 MW · 6 27 Apr 2019 · 23 MW · 8 28 Apr 2019 · 24 MW · 8 30 Apr 2019 · 2 MW · 1
20 Apr 25 Apr 28 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

39°high
49km/h · peak gust
19%lowest humidity

It had gone 0 days without rain (1 mm or more) when it started. Rain came after the fire: 1.1 mm on 1 May.

This area had burned before

99% of the perimeter overlaps earlier fires recorded since 2016: 3,138 ha in 2016, 2,973 ha in 2017, 664 ha in 2018. Part of it burned more than once, so the yearly figures add up to more than the 3,487 ha that had burned before.

How big is it?

10 km
It burned the equivalent of 2.2% of the area of London (35 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. Rapti Sonari where it started
    2,798 ha reached on 19 Apr
    2.7 %
  2. 749 ha reached on 21 Apr
    3.7 %

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 area0.10 ha
Residents< 20

Inside the perimeter there were about 0.10 hectares of built-up land and almost nobody lived there (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)
18 Apr 31.9 °C 31 % 31 km/h 0.4 mm Moderate 19
19 Apr 33.4 °C 24 % 32 km/h 0.1 mm High 30
20 Apr 34.0 °C 24 % 27 km/h 0.0 mm High 31
21 Apr 34.6 °C 29 % 21 km/h 0.0 mm High 29
22 Apr 34.0 °C 29 % 29 km/h 0.0 mm High 31
23 Apr 33.7 °C 38 % 34 km/h 0.0 mm High 28
24 Apr 34.4 °C 38 % 27 km/h 0.1 mm High 24
25 Apr 36.6 °C 36 % 40 km/h 0.0 mm High 27
26 Apr 38.1 °C 22 % 49 km/h 0.0 mm Very high 40
27 Apr 38.3 °C 21 % 38 km/h 0.0 mm High 35
28 Apr 38.4 °C 19 % 42 km/h 0.0 mm High 38
29 Apr 37.7 °C 22 % 34 km/h 0.0 mm High 36
30 Apr 38.6 °C 24 % 36 km/h 0.1 mm High 36
1 May after 39.3 °C 26 % 34 km/h 1.1 mm High 29

Its twins: fires that started in the same weather

It started with an FWI of 18.6, a minimum humidity of 31% and rain the day before. Fires in the area that started in weather like this since 2016: 27.

FWI at the start 18.6
Minimum humidity 31 %
Days without rain 0
this fire chosen twins rest of the area
Almost identicalSimilar

Outlines of the closest twins

Gaidakot fire, April 2023
2,865 ha 19 days FWI 19.6 Min. humidity 30 % 229 km away, in 2023

First rain (1 mm or more) after it ended: 1.7 mm on 29 Apr.

What happened to them

11 days
median duration
2,715 ha
median area
100 %
went past 1,000 ha
2.4 mm
rain at the end (median; 22 of 27 had it)

It burned an area similar to its twins (3,535 ha against a median of 2,715 ha) and lasted 13 days, against 11 days.

In 5 of 27, 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 2.4 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

1.1 mmfirst rain
1 Maythe day after it ended
49km/h · max. gust

It was considered over on 30 Apr, and on 1 May 1.1 mm fell. We do not know whether the rain or the firefighters put it out. Twins with rain when they ended: 22 of 27, with a median of 2.4 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 · 11 Apr 2019
After · 7 May 2019

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 · 100Every 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 Nepal

Frequently asked questions

How long did the Rapti Sonari fire last?
According to the heat detections seen by satellite inside the perimeter, it burned from 18 April 2019 to 30 April 2019 (13 days). The perimeter dates it from 19 April 2019 to 29 April 2019.
How much area did it burn?
The perimeter GWIS (Copernicus) rebuilt from heat detections is 3,535 hectares (35.4 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire entered 2 municipalities: Rapti Sonari (2,798 ha, 2.7 %); Babai (749 ha, 3.7 %).
What was the weather like?
During the fire the temperature reached 38.6 °C, humidity dropped to 19 % and gusts hit 49 km/h. The fire danger index (FWI) reached 40, class Very high.
Where does this data come from?
From the GWIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of Nepal (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: 27. Their median duration was 11 days and their median area 2,715 ha; 100 % went past 1,000 ha. In 5 of 27, 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 2.4 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: 101 · 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: 29 April 2019 → 30 April 2019.
  2. Start date: 19 April 2019 → 18 April 2019.

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 101.

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 19 April 2019 to 29 April 2019. 100 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 ADM3 (Creative Commons Attribution-ShareAlike 4.0 International License). 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.