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Valença do Piauí fire, September 2023 Valença do Piauí, Pimenteiras

Out · last detection 8 Oct 2023, 04:20 UTC

The fire started on 28 September 2023 in Valença do Piauí, Brazil, and satellites saw it burning for 11 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 6,012 hectares from heat detections, spread across 2 municipalities.

It is the 252th largest in Piaui since 2016 (of 803 with a page). Number 126 in Brazil in 2023, of 431.

Burnt area
6,012ha
GWIS perimeter (Copernicus)
Duration
11days
28 Sept 2023 – 8 Oct 2023
Municipalities hit
2
municipalities
Started on
28 Sept
2023
Heat detections
225
in a single hotspot: 210 MW
Danger at start
42
Very high · FWI index
Energy released
4.9GW
sum of detected power

Where it burned

8 Oct 2023
HOTSPOTS BY DAY 28 Sept8 Oct

How it evolved, day by day

28293012345678

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
40km/h · peak gust
19%lowest humidity

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

This area had burned before

87% of the perimeter overlaps earlier fires recorded since 2016: 3,433 ha in 2019, 4,217 ha in 2021. Part of it burned more than once, so the yearly figures add up to more than the 5,210 ha that had burned before.

What happened to each town

  1. Valença do Piauí 22,279 inhabitants where it started
    6,007 ha reached on 26 Sept
    4.5 %
  2. Pimenteiras 11,341 inhabitants
    43 ha
    0.0 %

Burnt area inside each municipality, from crossing the GWIS perimeter with administrative boundaries. The distance is from the town centre to the nearest fire: staying a kilometre away does not mean it reached the houses.

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)
26 Sept 37.4 °C 29 % 27 km/h 0.0 mm Very high 42
27 Sept 37.9 °C 25 % 34 km/h 0.0 mm Very high 47
28 Sept 38.2 °C 20 % 31 km/h 0.0 mm Extreme 51
29 Sept 38.9 °C 20 % 27 km/h 0.0 mm Very high 45
30 Sept 38.4 °C 22 % 38 km/h 0.0 mm Very high 49
1 Oct 38.3 °C 19 % 35 km/h 0.0 mm Very high 47
2 Oct 38.7 °C 20 % 34 km/h 0.0 mm Very high 49
3 Oct 39.0 °C 20 % 35 km/h 0.0 mm Very high 49
4 Oct 38.2 °C 23 % 38 km/h 0.0 mm Extreme 50
5 Oct 38.2 °C 23 % 37 km/h 0.0 mm Extreme 51
6 Oct 38.7 °C 20 % 40 km/h 0.0 mm Extreme 52
7 Oct 37.0 °C 25 % 37 km/h 0.0 mm Extreme 50
8 Oct 38.0 °C 22 % 34 km/h 0.0 mm Very high 47
9 Oct after 37.8 °C 23 % 32 km/h 0.0 mm Very high 46
10 Oct after 38.6 °C 23 % 31 km/h 0.0 mm Very high 46
11 Oct after 36.4 °C 26 % 33 km/h 0.0 mm Very high 48
12 Oct after 35.6 °C 32 % 37 km/h 0.1 mm Very high 44
13 Oct after 37.2 °C 26 % 38 km/h 0.0 mm Very high 43
14 Oct after 38.9 °C 23 % 36 km/h 0.0 mm Very high 45
15 Oct after 35.5 °C 32 % 38 km/h 0.0 mm Very high 45
16 Oct after 35.7 °C 27 % 37 km/h 0.0 mm Very high 42
17 Oct after 37.0 °C 19 % 34 km/h 0.0 mm Very high 45
18 Oct after 37.0 °C 19 % 34 km/h 0.0 mm Very high 44

Before and after, from space

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

Before · 21 Sept 2023
After · 15 Oct 2023

If the day is cloudy, change the date: each satellite passes once a day. In false colour the burnt ground looks brown or red.

The smoke

CAMS · Copernicus

On 2 October 2023 the air beside the fire reached 15 µg/m³ of PM2.5, but no daily average passed the WHO guideline (15).

PM2.5 peak15 µg/m³
Days over the guideline0 days
PM1022 µg/m³
Optical depth0.32
26272829301234567891011
Good Fair Moderate Poor Very poor Extremely poor

Particles from the Copernicus CAMS model at the centre of the perimeter; these are not measurements in each town. The pale bar is the worst hour, the solid one the daily average.

Open-Meteo.com (CC BY 4.0) · Copernicus Atmosphere Monitoring Service (CAMS)

Detections table · 225Every 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 Valença do Piauí fire last?
GWIS (Copernicus) dates it between 28 September 2023 and 8 October 2023: 11 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 6,012 hectares (60.1 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire entered 2 municipalities: Valença do Piauí (6,007 ha, 4.5 %); Pimenteiras (43 ha, 0.0 %).
What was the weather like?
During the fire the temperature reached 39.0 °C, humidity dropped to 19 % and gusts hit 40 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.

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

Satellite cross-check

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.

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.