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Floriano fire, August 2023 Floriano, São José do Peixe, Nazaré do Piauí

Out · last detection 17 Aug 2023, 16:33 UTC

The fire started on 3 August 2023 in Floriano, Brazil, and satellites saw it burning for 15 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 3,078 hectares from heat detections, spread across 3 municipalities.

It is the 770th largest in Piaui since 2016 (of 805 with a page). Number 412 in Brazil in 2023, of 431.

Compare with…

Suggestions: Nazaré do Piauí · 2018Nazaré do Piauí · 2019Nazaré do Piauí · 2026Nazaré do Piauí · 2018

Burnt area
3,078ha
GWIS perimeter (Copernicus)
Duration
15days
3 Aug 2023 – 17 Aug 2023
Municipalities hit
3
municipalities
Started on
3 Aug
2023
Heat detections
108
in a single hotspot: 49 MW
Danger at start
50
Extreme · FWI index
Average daily power
41MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 3 Aug17 Aug
17 Aug 2023

How it evolved, day by day

3 Aug 2023 · 80 MW · 5 4 Aug 2023 · 97 MW · 13 5 Aug 2023 · 78 MW · 22 6 Aug 2023 · 97 MW · 16 7 Aug 2023 · 64 MW · 14 8 Aug 2023 · 18 MW · 4 9 Aug 2023 · 5 MW · 1 10 Aug 2023 · 7 MW · 2 11 Aug 2023 · 41 MW · 8 12 Aug 2023 · 39 MW · 9 13 Aug 2023 · 35 MW · 8 14 Aug 2023 · 11 MW · 4 15 Aug 2023 · 1 MW · 1 17 Aug 2023 · 5 MW · 1
3 Aug 4 Aug 5 Aug 7 Aug 9 Aug 11 Aug 13 Aug 15 Aug

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

The weather it burned in

37°high
51km/h · peak gust
21%lowest humidity

It had gone 47 days without rain (1 mm or more) when it started.

This area had burned before

36% of the perimeter overlaps earlier fires recorded since 2016: 1,118 ha in 2018, 251 ha in 2021, 204 ha in 2022. Part of it burned more than once, so the yearly figures add up to more than the 1,114 ha that had burned before.

How big is it?

10 km
It burned the equivalent of 1.9% of the area of London (31 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. Floriano 62,036 inhabitants where it started
    2,563 ha reached on 3 Aug
    0.8 %
  2. São José do Peixe 3,297 inhabitants
    428 ha reached on 11 Aug
    0.3 %
  3. Nazaré do Piauí 6,665 inhabitants
    108 ha reached on 13 Aug
    0.1 %

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 2025
Built-up area< 0.1 ha
Residents< 20

Inside the perimeter there was no noticeable built-up land and almost nobody lived there (GHSL 2025, 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. The GHSL 2025 epoch is a projection made from 2020 and earlier data.

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)
3 Aug 34.7 °C 32 % 50 km/h 0.0 mm Extreme 50
4 Aug 36.0 °C 25 % 36 km/h 0.0 mm Very high 42
5 Aug 35.5 °C 27 % 36 km/h 0.0 mm Very high 42
6 Aug 35.9 °C 25 % 42 km/h 0.0 mm Very high 46
7 Aug 35.9 °C 28 % 44 km/h 0.0 mm Very high 47
8 Aug 36.6 °C 28 % 41 km/h 0.0 mm Very high 46
9 Aug 34.6 °C 28 % 46 km/h 0.0 mm Very high 48
10 Aug 34.5 °C 23 % 45 km/h 0.0 mm Very high 48
11 Aug 35.0 °C 23 % 44 km/h 0.0 mm Very high 48
12 Aug 35.0 °C 23 % 42 km/h 0.0 mm Very high 47
13 Aug 34.6 °C 23 % 44 km/h 0.0 mm Very high 48
14 Aug 34.9 °C 21 % 49 km/h 0.0 mm Extreme 51
15 Aug 34.7 °C 25 % 50 km/h 0.0 mm Extreme 51
16 Aug 35.1 °C 23 % 51 km/h 0.0 mm Extreme 52
17 Aug 34.4 °C 24 % 49 km/h 0.0 mm Extreme 52
18 Aug after 35.6 °C 26 % 42 km/h 0.0 mm Very high 48
19 Aug after 35.7 °C 28 % 40 km/h 0.0 mm Very high 48
20 Aug after 37.3 °C 24 % 38 km/h 0.0 mm Very high 47
21 Aug after 38.5 °C 24 % 38 km/h 0.0 mm Very high 46
22 Aug after 36.6 °C 30 % 35 km/h 0.0 mm Very high 42
23 Aug after 36.7 °C 27 % 38 km/h 0.0 mm Very high 47
24 Aug after 37.7 °C 23 % 31 km/h 0.0 mm Very high 42
25 Aug after 37.4 °C 23 % 21 km/h 0.0 mm Very high 41
26 Aug after 36.9 °C 29 % 29 km/h 0.0 mm Very high 42
27 Aug after 35.8 °C 36 % 27 km/h 0.1 mm High 36

Before and after, from space

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

Before · 27 Jul 2023
After · 24 Aug 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 10 August 2023 the air beside the fire reached 7 µg/m³ of PM2.5, but no daily average passed the WHO guideline (15).

PM2.5 peak7 µg/m³
Days over the guideline0 days
PM1010 µg/m³
Optical depth0.17
123456789101112131415161718
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 · 108Every 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 Floriano fire last?
According to the heat detections seen by satellite inside the perimeter, it burned from 3 August 2023 to 17 August 2023 (15 days). The perimeter dates it from 3 August 2023 to 15 August 2023.
How much area did it burn?
The perimeter GWIS (Copernicus) rebuilt from heat detections is 3,078 hectares (30.8 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire entered 3 municipalities: Floriano (2,563 ha, 0.8 %); São José do Peixe (428 ha, 0.3 %); Nazaré do Piauí (108 ha, 0.1 %).
What was the weather like?
During the fire the temperature reached 36.6 °C, humidity dropped to 21 % and gusts hit 51 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 · 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: 15 August 2023 → 17 August 2023.

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 adjusted with the VIIRS detections inside the perimeter, which said 3 August 2023 to 15 August 2023. 108 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 2025, 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.