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Baixa Grande do Ribeiro fire, 17 September 2017 Baixa Grande do Ribeiro

Out · last detection 1 Oct 2017, 04:33 UTC

The fire started on 17 September 2017 in Baixa Grande do Ribeiro, Brazil, and satellites saw it burning for 15 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 4,201 hectares from heat detections, spread across a single municipality.

It is the 404th largest in Piaui since 2016 (of 665 with a page). Number 600 in Brazil in 2017, of 994.

Burnt area
4,201ha
GWIS perimeter (Copernicus)
Duration
15days
17 Sept 2017 – 1 Oct 2017
Municipalities hit
1
municipalities
Started on
17 Sept
2017
Heat detections
160
in a single hotspot: 239 MW
Danger at start
54
Extreme · FWI index
Average daily power
125MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 17 Sept1 Oct
1 Oct 2017

How it evolved, day by day

17 Sept 2017 · 21 MW · 2 19 Sept 2017 · 13 MW · 2 20 Sept 2017 · 13 MW · 2 21 Sept 2017 · 65 MW · 14 22 Sept 2017 · 137 MW · 11 23 Sept 2017 · 12 MW · 1 24 Sept 2017 · 130 MW · 8 25 Sept 2017 · 189 MW · 22 26 Sept 2017 · 278 MW · 35 27 Sept 2017 · 115 MW · 25 28 Sept 2017 · 705 MW · 18 29 Sept 2017 · 62 MW · 16 30 Sept 2017 · 3 MW · 2 1 Oct 2017 · 2 MW · 2
17 Sept 21 Sept 24 Sept 28 Sept

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

The weather it burned in

38°high
49km/h · peak gust
21%lowest humidity

It had gone more than two months without rain (1 mm or more) when it started.

This area had burned before

5% of the perimeter overlaps earlier fires recorded since 2016: 211 ha in 2016.

How big is it?

10 km
It burned the equivalent of 2.7% of the area of London (42 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. Baixa Grande do Ribeiro 13,272 inhabitants where it started
    4,234 ha reached on 17 Sept
    0.5 %

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 2015
Built-up area< 0.1 ha
Residents< 20

Inside the perimeter there was no noticeable built-up land and almost nobody lived there (GHSL 2015, 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)
17 Sept 34.3 °C 28 % 49 km/h 0.0 mm Extreme 54
18 Sept 35.1 °C 24 % 46 km/h 0.0 mm Extreme 53
19 Sept 35.4 °C 24 % 47 km/h 0.0 mm Extreme 58
20 Sept 34.9 °C 25 % 47 km/h 0.0 mm Extreme 58
21 Sept 34.1 °C 24 % 49 km/h 0.0 mm Extreme 60
22 Sept 34.5 °C 25 % 44 km/h 0.0 mm Extreme 55
23 Sept 34.8 °C 26 % 40 km/h 0.0 mm Extreme 51
24 Sept 34.5 °C 23 % 42 km/h 0.0 mm Extreme 53
25 Sept 35.3 °C 25 % 42 km/h 0.0 mm Extreme 52
26 Sept 35.8 °C 24 % 44 km/h 0.0 mm Extreme 53
27 Sept 36.5 °C 25 % 43 km/h 0.0 mm Extreme 53
28 Sept 37.6 °C 21 % 43 km/h 0.0 mm Extreme 57
29 Sept 37.3 °C 23 % 43 km/h 0.0 mm Extreme 62
30 Sept 36.7 °C 23 % 42 km/h 0.0 mm Extreme 56
1 Oct 37.5 °C 22 % 33 km/h 0.0 mm Extreme 52
2 Oct after 38.0 °C 24 % 39 km/h 0.0 mm Extreme 60
3 Oct after 37.5 °C 23 % 34 km/h 0.0 mm Very high 44
4 Oct after 37.4 °C 19 % 39 km/h 0.0 mm Extreme 59
5 Oct after 36.8 °C 18 % 50 km/h 0.0 mm Very extreme 78
6 Oct after 36.5 °C 22 % 42 km/h 0.0 mm Extreme 63
7 Oct after 36.7 °C 25 % 40 km/h 0.0 mm Extreme 56
8 Oct after 36.1 °C 23 % 42 km/h 0.0 mm Extreme 51
9 Oct after 35.5 °C 28 % 35 km/h 0.0 mm Very high 45
10 Oct after 35.3 °C 30 % 35 km/h 0.0 mm Very high 46
11 Oct after 37.0 °C 25 % 38 km/h 0.0 mm Extreme 50

Its twins: fires that started in the same weather

It started with an FWI of 54.5, a minimum humidity of 28% and more than two months without rain. Fires in the area that started in weather like this since 2016: 58.

FWI at the start 54.5
Minimum humidity 28 %
Days without rain 60+
this fire chosen twins rest of the area
Almost identicalSimilar

Outlines of the closest twins

Tasso Fragoso fire, September 2021
3,024 ha 10 days FWI 53.1 Min. humidity 28 % 81 km away, in 2021

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

What happened to them

11 days
median duration
4,536 ha
median area
12 %
went past 10,000 ha
4.4 mm
rain at the end (median; 19 of 58 had it)

It burned an area similar to its twins (4,201 ha against a median of 4,536 ha) and lasted 15 days, against 11 days.

In 39 of 58, 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 4.4 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

—first rain
—no rain in ten days
49km/h · max. gust

It was considered over on 1 Oct, and not even 1 mm fell in the following ten days: it went out without rain. Twins with rain when they ended: 19 of 58, with a median of 4.4 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 · 10 Sept 2017
After · 8 Oct 2017

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 · 160Every 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 Baixa Grande do Ribeiro fire last?
According to the heat detections seen by satellite inside the perimeter, it burned from 17 September 2017 to 1 October 2017 (15 days). The perimeter dates it from 19 September 2017 to 29 September 2017.
How much area did it burn?
The perimeter GWIS (Copernicus) rebuilt from heat detections is 4,201 hectares (42.0 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire only entered Baixa Grande do Ribeiro (4,234 ha, 0.5 %).
What was the weather like?
During the fire the temperature reached 37.6 °C, humidity dropped to 21 % and gusts hit 49 km/h. The fire danger index (FWI) reached 62, 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: 58. Their median duration was 11 days and their median area 4,536 ha; 12 % went past 10,000 ha. In 39 of 58, 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 4.4 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: 193 · 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 September 2017 → 1 October 2017.
  2. Start date: 19 September 2017 → 17 September 2017.

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.
  • Dates adjusted with the VIIRS detections inside the perimeter, which said 19 September 2017 to 29 September 2017. 160 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 2015, 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.