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BR · Brazil · –

Rio Sono fire, 24 September 2020 Rio Sono

Out · last detection 9 Oct 2020, 17:08 UTC

The fire started on 24 September 2020 in Rio Sono, Brazil, and satellites saw it burning for 16 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 6,204 hectares from heat detections, spread across a single municipality.

It is the 364th largest in Tocantins since 2016 (of 1036 with a page). Number 386 in Brazil in 2020, of 957.

The power measured by the satellite is low (21.5 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
6,204ha
GWIS perimeter (Copernicus)
Duration
16days
24 Sept 2020 – 9 Oct 2020
Municipalities hit
1
municipalities
Started on
24 Sept
2020
Heat detections
167
in a single hotspot: 22 MW
Danger at start
57
Extreme · FWI index
Average daily power
61MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 24 Sept9 Oct
9 Oct 2020

How it evolved, day by day

24 Sept 2020 · 26 MW · 5 26 Sept 2020 · 9 MW · 1 27 Sept 2020 · 40 MW · 6 28 Sept 2020 · 56 MW · 17 29 Sept 2020 · 31 MW · 5 30 Sept 2020 · 34 MW · 3 1 Oct 2020 · 141 MW · 15 2 Oct 2020 · 136 MW · 20 3 Oct 2020 · 199 MW · 43 4 Oct 2020 · 104 MW · 35 5 Oct 2020 · 62 MW · 12 7 Oct 2020 · 3 MW · 2 8 Oct 2020 · 3 MW · 2 9 Oct 2020 · 7 MW · 1
24 Sept 28 Sept 3 Oct 8 Oct

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
45km/h · peak gust
13%lowest humidity

It had gone more than two months without rain (1 mm or more) when it started. Rain came after the fire: 12.0 mm on 11 Oct.

This area had burned before

14% of the perimeter overlaps earlier fires recorded since 2016: 849 ha in 2016.

How big is it?

10 km
It burned the equivalent of 3.9% of the area of London (62 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. Rio Sono 4,841 inhabitants where it started
    6,270 ha reached on 24 Sept
    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 2020
Built-up area0.21 ha
Residents< 20

Inside the perimeter there were about 0.21 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)

Started with Extreme FWI: 46 % of the area in Brazil 60 days without rain: 55 % of the area in Brazil

Day High Min. humidity Peak gust Rain Danger (FWI)
24 Sept 37.5 °C 25 % 45 km/h 0.0 mm Extreme 57
25 Sept 35.0 °C 28 % 45 km/h 0.0 mm Extreme 58
26 Sept 35.0 °C 27 % 38 km/h 0.0 mm Extreme 52
27 Sept 37.2 °C 21 % 30 km/h 0.0 mm Very high 47
28 Sept 38.8 °C 16 % 27 km/h 0.0 mm Extreme 53
29 Sept 38.4 °C 21 % 34 km/h 0.0 mm Extreme 56
30 Sept 37.3 °C 23 % 27 km/h 0.0 mm Very high 46
1 Oct 38.0 °C 16 % 36 km/h 0.0 mm Extreme 55
2 Oct 38.4 °C 13 % 30 km/h 0.0 mm Extreme 55
3 Oct 38.9 °C 15 % 31 km/h 0.0 mm Extreme 60
4 Oct 38.7 °C 18 % 22 km/h 0.0 mm Extreme 53
5 Oct 37.1 °C 27 % 27 km/h 0.0 mm Very high 48
6 Oct 38.1 °C 18 % 33 km/h 0.0 mm Extreme 57
7 Oct 39.0 °C 17 % 29 km/h 0.0 mm Extreme 53
8 Oct 38.5 °C 23 % 22 km/h 0.0 mm Very high 45
9 Oct 37.7 °C 30 % 29 km/h 0.0 mm Very high 46
10 Oct after 32.3 °C 43 % 34 km/h 0.6 mm Very high 44
11 Oct after 29.9 °C 52 % 24 km/h 12.0 mm High 22

Its twins: fires that started in the same weather

It started with an FWI of 56.9, a minimum humidity of 25% and more than two months without rain. Fires in the area that started in weather like this since 2016: 17.

FWI at the start 56.9
Minimum humidity 25 %
Days without rain 60+
this fire chosen twins rest of the area
Almost identicalSimilar

Outlines of the closest twins

Tocantínia fire, August 2022
3,297 ha 6 days FWI 56.1 Min. humidity 25 % 53 km away, in 2022

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

What happened to them

8 days
median duration
3,915 ha
median area
0 %
went past 10,000 ha
8.9 mm
rain at the end (median; 7 of 17 had it)

It was 1.6 times larger than the median of its twins and lasted 16 days, against 8 days.

Only 2 of its 17 twins burned more. The weather on the first day does not explain everything: the wind in the following days, the fuel and the firefighting also count. In 10 of 17, 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 8.9 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

12.0 mmfirst rain
11 Oct2 days after it ended
45km/h · max. gust

It was considered over on 9 Oct, and on 11 Oct 12.0 mm fell. We do not know whether the rain or the firefighters put it out. Twins with rain when they ended: 7 of 17, with a median of 8.9 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 Sept 2020
After · 16 Oct 2020

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 · 167Every 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 Brazil

Frequently asked questions

How long did the Rio Sono fire last?
According to the heat detections seen by satellite inside the perimeter, it burned from 24 September 2020 to 9 October 2020 (16 days). The perimeter dates it from 24 September 2020 to 8 October 2020.
How much area did it burn?
The perimeter GWIS (Copernicus) rebuilt from heat detections is 6,204 hectares (62.0 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire only entered Rio Sono (6,270 ha, 1.0 %).
What was the weather like?
During the fire the temperature reached 39.0 °C, humidity dropped to 13 % and gusts hit 45 km/h. The fire danger index (FWI) reached 60, class Extreme.
Where does this data come from?
From the GWIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of Brazil (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: 17. Their median duration was 8 days and their median area 3,915 ha; 0 % went past 10,000 ha. Only 2 of its 17 twins burned more. The weather on the first day does not explain everything: the wind in the following days, the fuel and the firefighting also count. In 10 of 17, 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 8.9 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: 193 · Emergency number and official warnings

Satellite cross-check

History of this page · 1 Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.
  1. Last day with fire: 8 October 2020 → 9 October 2020.

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 193.

How we know this
  • Perimeter: GWIS (Copernicus), rebuilt from heat detections rather than mapped on imagery; 2 polygons grouped in this page.
  • Dates adjusted with the VIIRS detections inside the perimeter, which said 24 September 2020 to 8 October 2020. 167 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 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.