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Baixa Grande do Ribeiro fire, September 2018 Baixa Grande do Ribeiro, Santa Filomena

Out · last detection 23 Sept 2018, 04:39 UTC

The fire started on 17 September 2018 in Baixa Grande do Ribeiro, Brazil, and satellites saw it burning for 10 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 3,212 hectares from heat detections, spread across 2 municipalities.

It is the 597th largest in Piaui since 2016 (of 665 with a page). Number 261 in Brazil in 2018, of 291.

Burnt area
3,212ha
GWIS perimeter (Copernicus)
Duration
10days
17 Sept 2018 – 26 Sept 2018
Municipalities hit
2
municipalities
Started on
17 Sept
2018
Heat detections
98
in a single hotspot: 185 MW
Danger at start
42
Very high · FWI index
Average daily power
757MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 17 Sept26 Sept
23 Sept 2018

How it evolved, day by day

17 Sept 2018 · 3,692 MW · 85 18 Sept 2018 · 74 MW · 10 19 Sept 2018 · 2 MW · 1 21 Sept 2018 · 15 MW · 1 23 Sept 2018 · 2 MW · 1
17 Sept 18 Sept 19 Sept 21 Sept 23 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
46km/h · peak gust
17%lowest humidity

It had gone 10 days without rain (1 mm or more) when it started. Rain came after the fire: 5.0 mm on 5 Oct.

This area had burned before

6% of the perimeter overlaps earlier fires recorded since 2016: 179 ha in 2017.

How big is it?

10 km
It burned the equivalent of 2% of the area of London (32 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
    3,225 ha reached on 17 Sept
    0.4 %
  2. Santa Filomena 6,087 inhabitants
    12 ha
    0.0 %

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 area0.94 ha
Residents≈ 30

Inside the perimeter there were about 0.94 hectares of built-up land and about 30 residents (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)
17 Sept 36.7 °C 28 % 42 km/h 0.0 mm Very high 42
18 Sept 36.3 °C 27 % 34 km/h 0.0 mm Very high 46
19 Sept 36.8 °C 26 % 32 km/h 0.0 mm Very high 42
20 Sept 36.1 °C 24 % 40 km/h 0.0 mm Very high 48
21 Sept 36.4 °C 24 % 46 km/h 0.0 mm Very high 50
22 Sept 38.0 °C 17 % 36 km/h 0.0 mm Extreme 52
23 Sept 37.4 °C 25 % 30 km/h 0.0 mm Very high 50
24 Sept 34.3 °C 33 % 35 km/h 0.0 mm Very high 47
25 Sept 35.0 °C 31 % 36 km/h 0.0 mm Very high 45
26 Sept 36.5 °C 26 % 38 km/h 0.0 mm Very high 48
27 Sept after 36.6 °C 28 % 33 km/h 0.0 mm Very high 46
28 Sept after 37.4 °C 25 % 28 km/h 0.0 mm Very high 45
29 Sept after 37.3 °C 26 % 28 km/h 0.0 mm Very high 44
30 Sept after 36.6 °C 28 % 34 km/h 0.0 mm Very high 50
1 Oct after 35.8 °C 30 % 26 km/h 0.1 mm Very high 42
2 Oct after 37.1 °C 24 % 34 km/h 0.0 mm Very high 50
3 Oct after 37.1 °C 28 % 31 km/h 0.0 mm Very high 49
4 Oct after 36.4 °C 30 % 25 km/h 0.0 mm Very high 46
5 Oct after 34.6 °C 41 % 29 km/h 5.0 mm High 28

Its twins: fires that started in the same weather

It started with an FWI of 42.1, a minimum humidity of 28% and 10 days without rain. Fires in the area that started in weather like this since 2016: 42.

FWI at the start 42.1
Minimum humidity 28 %
Days without rain 10
this fire chosen twins rest of the area
Almost identicalSimilar

Outlines of the closest twins

Baixa Grande do Ribeiro fire, October 2016
8,770 ha 4 days FWI 40.7 Min. humidity 28 % 54 km away, in 2016

First rain (1 mm or more) after it ended: 1.2 mm on 20 Oct.

What happened to them

10 days
median duration
3,838 ha
median area
10 %
went past 10,000 ha
3.1 mm
rain at the end (median; 25 of 42 had it)

It burned an area similar to its twins (3,212 ha against a median of 3,838 ha) and lasted 10 days, against 10 days.

In 17 of 42, 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 3.1 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

5.0 mmfirst rain
5 Oct9 days after it ended
46km/h · max. gust

It was considered over on 26 Sept, and on 5 Oct 5.0 mm fell. We do not know whether the rain or the firefighters put it out. Twins with rain when they ended: 25 of 42, with a median of 3.1 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 2018
After · 3 Oct 2018

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 · 98Every 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 2018 to 26 September 2018 (10 days). The perimeter dates it from 17 September 2018 to 19 September 2018.
How much area did it burn?
The perimeter GWIS (Copernicus) rebuilt from heat detections is 3,212 hectares (32.1 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire entered 2 municipalities: Baixa Grande do Ribeiro (3,225 ha, 0.4 %); Santa Filomena (12 ha, 0.0 %).
What was the weather like?
During the fire the temperature reached 38.0 °C, humidity dropped to 17 % and gusts hit 46 km/h. The fire danger index (FWI) reached 52, 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: 42. Their median duration was 10 days and their median area 3,838 ha; 10 % went past 10,000 ha. In 17 of 42, 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 3.1 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: 19 September 2018 → 26 September 2018.

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 17 September 2018 to 19 September 2018. 98 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.