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Parnaguá fire, 18 September 2018 Parnaguá, Riacho Frio

Out · last detection 29 Sept 2018, 17:02 UTC

The fire started on 18 September 2018 in Parnaguá, Brazil, and satellites saw it burning for 12 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 3,905 hectares from heat detections, spread across 2 municipalities.

It is the 523th largest in Piaui since 2016 (of 805 with a page). Number 170 in Brazil in 2018, of 291.

Compare with…

Suggestions: Riacho Frio · 2018Riacho Frio · 2022Riacho Frio · 2021Riacho Frio · 2026

Burnt area
3,905ha
GWIS perimeter (Copernicus)
Duration
12days
18 Sept 2018 – 29 Sept 2018
Municipalities hit
2
municipalities
Started on
18 Sept
2018
Heat detections
113
in a single hotspot: 69 MW
Danger at start
44
Very high · FWI index
Average daily power
156MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 18 Sept29 Sept
29 Sept 2018

How it evolved, day by day

18 Sept 2018 · 33 MW · 3 19 Sept 2018 · 198 MW · 9 20 Sept 2018 · 32 MW · 10 21 Sept 2018 · 200 MW · 10 22 Sept 2018 · 257 MW · 17 23 Sept 2018 · 516 MW · 31 24 Sept 2018 · 19 MW · 14 26 Sept 2018 · 15 MW · 3 27 Sept 2018 · 199 MW · 12 29 Sept 2018 · 91 MW · 4
18 Sept 20 Sept 22 Sept 23 Sept 24 Sept 27 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
42km/h · peak gust
18%lowest humidity

It had gone 7 days without rain (1 mm or more) when it started.

This area had burned before

No earlier perimeters overlap this fire since 2016, when the satellite record begins.

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. Parnaguá 10,103 inhabitants where it started
    3,423 ha reached on 18 Sept
    1.0 %
  2. Riacho Frio 4,165 inhabitants
    505 ha reached on 23 Sept
    0.2 %

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)
14 Sept 34.6 °C 24 % 40 km/h 0.0 mm Very high 44
15 Sept 35.4 °C 27 % 36 km/h 0.0 mm Very high 41
16 Sept 38.1 °C 22 % 36 km/h 0.0 mm Very high 45
17 Sept 38.0 °C 20 % 36 km/h 0.0 mm Very high 45
18 Sept 37.7 °C 25 % 29 km/h 0.0 mm Very high 47
19 Sept 38.5 °C 21 % 37 km/h 0.0 mm Very high 47
20 Sept 37.3 °C 18 % 41 km/h 0.0 mm Extreme 51
21 Sept 37.0 °C 23 % 42 km/h 0.0 mm Extreme 51
22 Sept 38.4 °C 20 % 31 km/h 0.0 mm Very high 47
23 Sept 37.6 °C 27 % 38 km/h 0.0 mm Very high 48
24 Sept 35.7 °C 34 % 34 km/h 0.0 mm Very high 40
25 Sept 36.3 °C 30 % 39 km/h 0.0 mm Very high 44
26 Sept 37.0 °C 26 % 39 km/h 0.0 mm Very high 44
27 Sept 37.5 °C 26 % 37 km/h 0.0 mm Very high 42
28 Sept 38.4 °C 24 % 34 km/h 0.0 mm Very high 42
29 Sept 38.2 °C 24 % 23 km/h 0.0 mm Very high 39
30 Sept after 37.3 °C 28 % 31 km/h 0.0 mm Very high 41
1 Oct after 36.4 °C 30 % 34 km/h 0.0 mm Very high 43
2 Oct after 37.2 °C 25 % 34 km/h 0.0 mm Very high 43
3 Oct after 37.0 °C 28 % 34 km/h 0.0 mm Very high 42
4 Oct after 39.0 °C 25 % 23 km/h 0.0 mm Very high 38
5 Oct after 36.6 °C 32 % 31 km/h 0.0 mm Very high 40
6 Oct after 35.8 °C 33 % 36 km/h 0.0 mm Very high 41
7 Oct after 35.9 °C 32 % 38 km/h 0.0 mm Very high 42
8 Oct after 37.0 °C 26 % 35 km/h 0.0 mm Very high 41
9 Oct after 37.2 °C 24 % 36 km/h 0.0 mm Very high 43

Before and after, from space

Drag the line to compare the same ground before the fire and after it.

Before · 11 Sept 2018
After · 6 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 · 113Every 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 Parnaguá fire last?
GWIS (Copernicus) dates it between 18 September 2018 and 29 September 2018: 12 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 3,905 hectares (39.0 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire entered 2 municipalities: Parnaguá (3,423 ha, 1.0 %); Riacho Frio (505 ha, 0.2 %).
What was the weather like?
During the fire the temperature reached 38.5 °C, humidity dropped to 18 % and gusts hit 42 km/h. The fire danger index (FWI) reached 51, 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.

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.

No changes since 24 October 2026.

RSS Changes to this page

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. 113 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.