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BR · Brazil · –

Rio Sono fire, 5 October 2020 Rio Sono

Out · last detection 10 Oct 2020, 04:14 UTC

The fire started on 5 October 2020 in Rio Sono, Brazil, and satellites saw it burning for 6 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 3,948 hectares from heat detections, spread across a single municipality.

It is the 686th largest in Tocantins since 2016 (of 1036 with a page). Number 656 in Brazil in 2020, of 957.

Burnt area
3,948ha
GWIS perimeter (Copernicus)
Duration
6days
5 Oct 2020 – 10 Oct 2020
Municipalities hit
1
municipalities
Started on
5 Oct
2020
Heat detections
73
in a single hotspot: 71 MW
Danger at start
49
Very high · FWI index
Average daily power
231MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 5 Oct10 Oct
10 Oct 2020

How it evolved, day by day

5 Oct 2020 · 341 MW · 12 7 Oct 2020 · 457 MW · 23 8 Oct 2020 · 332 MW · 25 9 Oct 2020 · 12 MW · 7 10 Oct 2020 · 15 MW · 6
5 Oct 7 Oct 8 Oct 9 Oct 10 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

40°high
37km/h · peak gust
11%lowest humidity

It had gone more than two months without rain (1 mm or more) when it started. Rain came after the fire: 5.5 mm on 11 Oct.

This area had burned before

17% of the perimeter overlaps earlier fires recorded since 2016: 2 ha in 2016, 686 ha in 2019.

How big is it?

10 km
It burned the equivalent of 2.5% of the area of London (39 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
    3,974 ha reached on 5 Oct
    0.6 %

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 area< 0.1 ha
Residents< 20

Inside the perimeter there was no noticeable 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)
28 Sept 39.7 °C 14 % 29 km/h 0.0 mm Very high 49
29 Sept 39.6 °C 17 % 34 km/h 0.0 mm Extreme 53
30 Sept 38.3 °C 20 % 31 km/h 0.0 mm Extreme 52
1 Oct 38.9 °C 14 % 36 km/h 0.0 mm Extreme 54
2 Oct 40.0 °C 12 % 33 km/h 0.0 mm Extreme 52
3 Oct 40.0 °C 12 % 31 km/h 0.0 mm Extreme 51
4 Oct 40.0 °C 17 % 27 km/h 0.0 mm Very high 50
5 Oct 39.4 °C 19 % 34 km/h 0.0 mm Extreme 53
6 Oct 39.2 °C 15 % 37 km/h 0.0 mm Extreme 57
7 Oct 40.5 °C 11 % 34 km/h 0.0 mm Extreme 56
8 Oct 39.8 °C 16 % 23 km/h 0.0 mm Extreme 51
9 Oct 39.1 °C 26 % 32 km/h 0.1 mm Very high 46
10 Oct 34.1 °C 38 % 36 km/h 1.5 mm High 32
11 Oct after 30.7 °C 51 % 32 km/h 5.5 mm Low 7

Its twins: fires that started in the same weather

It started with an FWI of 49.3, a minimum humidity of 19% and more than two months without rain. Fires in the area that started in weather like this since 2016: 30.

FWI at the start 49.3
Minimum humidity 19 %
Days without rain 60+
this fire chosen twins rest of the area
Almost identicalSimilar

Outlines of the closest twins

Ponte Alta do Tocantins fire, September 2022
3,654 ha 5 days FWI 48.9 Min. humidity 19 % 128 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
5,493 ha
median area
23 %
went past 10,000 ha
4.8 mm
rain at the end (median; 13 of 30 had it)

It burned an area similar to its twins (3,948 ha against a median of 5,493 ha) and lasted 6 days, against 8 days.

In 17 of 30, 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 4.8 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

5.5 mmfirst rain
11 Octthe day after it ended
37km/h · max. gust

It was considered over on 10 Oct, and on 11 Oct 5.5 mm fell. We do not know whether the rain or the firefighters put it out. Twins with rain when they ended: 13 of 30, with a median of 4.8 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 · 28 Sept 2020
After · 17 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 · 73Every 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?
GWIS (Copernicus) dates it between 5 October 2020 and 10 October 2020: 6 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 3,948 hectares (39.5 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire only entered Rio Sono (3,974 ha, 0.6 %).
What was the weather like?
During the fire the temperature reached 40.5 °C, humidity dropped to 11 % and gusts hit 37 km/h. The fire danger index (FWI) reached 57, 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: 30. Their median duration was 8 days and their median area 5,493 ha; 23 % went past 10,000 ha. In 17 of 30, 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 4.8 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 Changes in area, dates, name, official record or merged pages, compared every night 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
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.
  • Dates from the perimeter: the VIIRS detections inside it did not change them. 73 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.