How long did the Floriano fire last?

According to the heat detections seen by satellite inside the perimeter, it burned from 5 July 2021 to 25 July 2021 (21 days). The perimeter dates it from 5 July 2021 to 24 July 2021.

How much area did it burn?

The perimeter GWIS (Copernicus) rebuilt from heat detections is 6,518 hectares (65.2 km²). It is an estimate: official national figures may differ.

Which municipalities burned?

The fire entered 2 municipalities: Floriano (5,419 ha, 1.6 %); Nazaré do Piauí (1,141 ha, 0.9 %).

What was the weather like?

During the fire the temperature reached 36.6 °C, humidity dropped to 25 % and gusts hit 54 km/h. The fire danger index (FWI) reached 55, 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.

BR · Brazil · 2021-07-05 → 2021-07-25

Floriano fire, July 2021 Floriano, Nazaré do Piauí

Out · last detection 25 Jul 2021, 16:50 UTC

The fire started on 5 July 2021 in Floriano, Brazil, and satellites saw it burning for 21 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 6,518 hectares from heat detections, spread across 2 municipalities.

It is the 221th largest in Piaui since 2016 (of 805 with a page). Number 272 in Brazil in 2021, of 814.

The power measured by the satellite is low (18.3 MW in the strongest hotspot), more typical of grass or stubble burning, or a slow surface fire, than of a large crown fire.

Compare with…

Suggestions: Floriano · 2016 Nazaré do Piauí · 2019 Nazaré do Piauí · 2026 Amarante · 2025

Burnt area: 6,518ha; GWIS perimeter (Copernicus)
Duration: 21days; 5 Jul 2021 – 25 Jul 2021
Municipalities hit: 2; municipalities
Started on: 5 Jul; 2021
Heat detections: 265; in a single hotspot: 18 MW
Danger at start: 38; Very high · FWI index
Average daily power: 72MW; detected power per day, on average

HOTSPOTS BY DAY 5 Jul25 Jul

Play back 25 Jul 2021

How it evolved, day by day

5 Jul 8 Jul 11 Jul 13 Jul 14 Jul 17 Jul 20 Jul 23 Jul

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

54km/h · peak gust

25%lowest humidity

It had gone more than two months 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?

It burned the equivalent of 4.1% of the area of London (65 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

Floriano 62,036 inhabitants where it started

5,419 ha reached on 5 Jul

1.6 %
Nazaré do Piauí 6,665 inhabitants

1,141 ha reached on 13 Jul

0.9 %

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	Danger (FWI)
5 Jul	33.8 °C	34 %	44 km/h	Very high 38
6 Jul	34.4 °C	31 %	40 km/h	High 38
7 Jul	34.8 °C	32 %	39 km/h	High 37
8 Jul	34.8 °C	28 %	41 km/h	Very high 42
9 Jul	33.6 °C	34 %	42 km/h	Very high 43
10 Jul	35.2 °C	30 %	43 km/h	Very high 42
11 Jul	32.9 °C	39 %	45 km/h	Very high 41
12 Jul	34.6 °C	34 %	46 km/h	Very high 40
13 Jul	34.0 °C	30 %	47 km/h	Very high 43
14 Jul	34.4 °C	30 %	43 km/h	Very high 41
15 Jul	33.7 °C	37 %	42 km/h	Very high 41
16 Jul	35.2 °C	30 %	39 km/h	Very high 39
17 Jul	35.5 °C	31 %	31 km/h	High 36
18 Jul	35.3 °C	28 %	39 km/h	Very high 41
19 Jul	35.9 °C	25 %	32 km/h	Very high 39
20 Jul	36.6 °C	27 %	37 km/h	Very high 42
21 Jul	34.9 °C	30 %	45 km/h	Very high 47
22 Jul	34.1 °C	27 %	49 km/h	Very high 50
23 Jul	33.8 °C	28 %	54 km/h	Extreme 53
24 Jul	34.0 °C	28 %	52 km/h	Extreme 55
25 Jul	34.1 °C	27 %	50 km/h	Very high 50
26 Jul after	34.8 °C	28 %	48 km/h	Very high 49
27 Jul after	35.4 °C	29 %	40 km/h	Very high 46
28 Jul after	35.4 °C	32 %	38 km/h	Very high 44
29 Jul after	35.4 °C	33 %	18 km/h	High 33
30 Jul after	36.9 °C	21 %	36 km/h	Very high 46
31 Jul after	35.5 °C	28 %	51 km/h	Extreme 55
1 Aug after	32.0 °C	35 %	59 km/h	Extreme 51
2 Aug after	33.7 °C	26 %	50 km/h	Very high 47
3 Aug after	34.9 °C	26 %	41 km/h	Very high 42

Before and after, from space

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

↔

Before · 28 Jun 2021

After · 1 Aug 2021

Before After

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 · 265Every 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 time	Satellite	FRP (MW)	Lat	Lon

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 5 July 2021 to 25 July 2021 (21 days). The perimeter dates it from 5 July 2021 to 24 July 2021.
How much area did it burn?: The perimeter GWIS (Copernicus) rebuilt from heat detections is 6,518 hectares (65.2 km²). It is an estimate: official national figures may differ.
Which municipalities burned?: The fire entered 2 municipalities: Floriano (5,419 ha, 1.6 %); Nazaré do Piauí (1,141 ha, 0.9 %).
What was the weather like?: During the fire the temperature reached 36.6 °C, humidity dropped to 25 % and gusts hit 54 km/h. The fire danger index (FWI) reached 55, 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 ›

INPE · Programa Queimadas ↗
IBAMA · Prevfogo ↗

Satellite cross-check

NASA FIRMS ↗
GWIS · Copernicus ↗

History of this page · 1 Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.

25 October 2026 Last day with fire: 24 July 2021 → 25 July 2021.

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.

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What really happened?

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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 5 July 2021 to 24 July 2021. 265 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.

Where it burned