Burned area
satellite only3,285ha
Perimeter published by GWIS (Copernicus).
- Source
- GWIS (Copernicus)
- Date
- 23 Sept 2025 – 12 Oct 2025
+− cross-check
No official record is matched to this page to compare it with.
BR · Brazil · –
Floriano fire, 23 September 2025 Floriano
Out · last detection 12 Oct 2025, 15:38 UTC
The fire started on 23 September 2025 in Floriano, Brazil, and satellites saw it burning for 20 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 3,285 hectares from heat detections, spread across a single municipality.
It is the 573th largest in Piaui since 2016 (of 665 with a page). Number 464 in Brazil in 2025, of 526.
The power measured by the satellite is low (26.1 MW in the strongest hotspot), more typical of grass or stubble burning, or a slow surface fire, than of a large crown fire.
Use this data
Compare with…
Use this data
Fire page data · version 2026-10-25matches the official recordwith caveatssatellite onlymodel
When copying, the sentence is
Tick the figures you want: they make up the lede and the CSV.
Duration by satellite
satellite only20days
23 Sept 2025 to 12 Oct 2025: first and last day with fire on the page.
- Source
- GWIS (Copernicus) · NASA FIRMS · VIIRS
- Date
- last detection: 12 Oct 2025, 15:38 UTC
+− cross-check
Satellites pass a few times a day and cloud or smoke can hide the fire: a lack of detections is not an official extinction. Each country’s emergency service declares a fire contained or out.
Start
satellite only23 Sept 2025
First day with fire seen by the satellites or the perimeter.
- Source
- GWIS (Copernicus) · NASA FIRMS · VIIRS
- Date
- 23 Sept 2025
+− cross-check
No official record is matched to this page, so the alert time and the cause are not known here.
Hotspots
satellite only121
VIIRS detections at 375 m. Most intense hotspot: 26 MW.
- Source
- NASA FIRMS · VIIRS (Suomi NPP)
- Date
- 23 Sept 2025 – 12 Oct 2025
+− cross-check
There is no official record to compare with. Each hotspot is a pixel detected in one satellite pass, not a separate fire.
The worst day
satellite only150MW
Total radiative power on 28 September 2025; hotspots that day: 17.
- Source
- NASA FIRMS · VIIRS (FRP)
- Date
- 28 Sept 2025
+− cross-check
Fire radiative power (FRP) measures the energy the fire gives off when the satellite passes. Added up by day, it compares intensity, not area.
Danger at the start
model48.2FWI · very high
Fire Weather Index (Canadian system) computed by WorldFires for the day the fire started. Consecutive days without rain before: 60.
- Source
- WorldFires calculation (Canadian FWI system)
- Date
- 23 Sept 2025, local noon
- Model
- ERA5 0,25° (ECMWF · Copernicus C3S) · Open-Meteo.com
+− cross-check
This is an index computed from weather model data, not a measurement of the fire nor an official warning. Danger warnings are issued by each country’s authority. Emergency number and official warnings
Weather during the fire
model39.1°C · 22% RH
High of 39.1 °C and minimum humidity of 22% on 8 October 2025; gusts of 55 km/h on 4 October 2025.
- Source
- weather model at the fire’s grid cell
- Date
- 23 Sept 2025 – 12 Oct 2025
- Model
- ERA5 0,25° (ECMWF · Copernicus C3S) · Open-Meteo.com
+− cross-check
These are model values for a cell of about 25 km, not from a weather station: they may differ from what was measured on the ground.
This page’s change log has been kept since 24 October 2026: every night what it publishes is compared and the difference is logged. Anything earlier is reconstructed from each source’s date and marked as reconstructed.
Show
-
· reconstructed weatherWeather and FWI computed from the ERA5 reanalysis
-
logLast day with fire: 6 October 2025 → 12 October 2025.
-
· reconstructed GHSLPopulation and built-up area computed
What was saved on 25 October 2026
Every night a snapshot of what the page shows is saved. If anything changes, it appears in the list as a log entry.
- Area
- 3,285 ha
- Dates
- 23 Sept 2025 – 12 Oct 2025
- Name
- Floriano
- Official record
- —
Versioned permanent link
https://worldfires.org/en/fire/floriano-2025-09-2?v=2026-10-25A version keeps the area, dates, name and official record; the area as it was logged (changes under 2% are not logged). The map, hotspots and weather always show today’s data.
Citation
A lede of about 60 words figures only, no adjectives
CSV for this fire floriano-2025-09-2.csv · daily, no individual hotspots
| fecha | focos_viirs | frp_mw | tmax_c | tmin_c | hr_min_pct | viento_max_kmh | racha_max_kmh | precip_mm | fwi | clase_fwi | dentro_del_incendio |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 2025-09-23 | 1 | 4 | 38.6 | 26.4 | 26 | 18.2 | 42.5 | 0 | 48.2 | muy_alto | 1 |
| 2025-09-24 | 4 | 17 | 37.7 | 27.4 | 24 | 19.3 | 44.3 | 0 | 57.7 | extremo | 1 |
| 2025-09-25 | 13 | 57 | 37 | 26.6 | 20 | 24.2 | 52.6 | 0 | 62.9 | extremo | 1 |
| 2025-09-26 | 12 | 33 | 37 | 26.3 | 24 | 23.1 | 50 | 0 | 59.6 | extremo | 1 |
| 2025-09-27 | 26 | 78 | 36.8 | 26.2 | 21 | 25 | 52.9 | 0 | 65.5 | extremo | 1 |
| 2025-09-28 | 17 | 150 | 36.5 | 24 | 22 | 24.1 | 51.8 | 0 | 61.3 | extremo | 1 |
| 2025-09-29 | 17 | 140 | 36.7 | 25.1 | 24 | 22 | 47.9 | 0 | 58 | extremo | 1 |
| 2025-09-30 | 3 | 20 | 37.1 | 25.4 | 22 | 23.4 | 50 | 0 | 60.4 | extremo | 1 |
| 2025-10-01 | 1 | 4 | 37.2 | 25.6 | 24 | 21.9 | 47.9 | 0 | 57.9 | extremo | 1 |
| 2025-10-02 | 3 | 13 | 38 | 25.4 | 21 | 22.1 | 47.2 | 0 | 59.7 | extremo | 1 |
| 2025-10-03 | 6 | 15 | 37.1 | 26 | 20 | 23.8 | 51.8 | 0 | 59.7 | extremo | 1 |
| 2025-10-04 | 3 | 19 | 37.2 | 25 | 17 | 25 | 54.7 | 0 | 70.8 | muy_extremo | 1 |
| 2025-10-05 | 7 | 81 | 37.7 | 26.2 | 21 | 23 | 50.4 | 0 | 66.4 | extremo | 1 |
| 2025-10-06 | 0 | 0 | 38 | 26.7 | 21 | 22.9 | 49.7 | 0 | 60.8 | extremo | 1 |
| 2025-10-07 | 0 | 0 | 38.2 | 26.7 | 22 | 19.1 | 41 | 0 | 54.8 | extremo | 1 |
| 2025-10-08 | 2 | 20 | 39.1 | 27.6 | 22 | 20.9 | 46.8 | 0 | 56.8 | extremo | 1 |
| 2025-10-09 | 2 | 6 | 38.3 | 28.3 | 23 | 22.4 | 48.2 | 0 | 60.1 | extremo | 1 |
| 2025-10-10 | 1 | 8 | 38.5 | 26.5 | 21 | 22.8 | 50 | 0 | 62.2 | extremo | 1 |
| 2025-10-11 | 0 | 0 | 38.3 | 26.7 | 22 | 21.2 | 45 | 0 | 55.3 | extremo | 1 |
| 2025-10-12 | 3 | 15 | 38.7 | 27.2 | 21 | 19.9 | 43.2 | 0 | 55.3 | extremo | 1 |
| 2025-10-13 | 0 | 0 | 38.1 | 27 | 25 | 19.3 | 45.4 | 0 | 55 | extremo | 0 |
| 2025-10-14 | 0 | 0 | 38.6 | 28.1 | 18 | 15.5 | 35.3 | 0 | 59.6 | extremo | 0 |
| 2025-10-15 | 0 | 0 | 38.7 | 26.2 | 19 | 20.2 | 43.6 | 0 | 65.8 | extremo | 0 |
| 2025-10-16 | 0 | 0 | 38.4 | 27.1 | 16 | 23.1 | 49 | 0 | 66.2 | extremo | 0 |
| 2025-10-17 | 0 | 0 | 38.7 | 25.4 | 19 | 21.8 | 46.1 | 0 | 56.6 | extremo | 0 |
| 2025-10-18 | 0 | 0 | 38 | 27.1 | 26 | 17.1 | 39.6 | 0 | 52 | extremo | 0 |
| 2025-10-19 | 0 | 0 | 38.2 | 26.9 | 29 | 11.2 | 31.3 | 0 | 44.5 | muy_alto | 0 |
| 2025-10-20 | 0 | 0 | 32.8 | 24.2 | 45 | 13 | 27.7 | 0.9 | 28 | alto | 0 |
| 2025-10-21 | 0 | 0 | 31.9 | 24 | 44 | 27.3 | 55.1 | 3.7 | 23.2 | alto | 0 |
It is generated in your browser from this page’s data: one file per fire, aggregated by day and without individual hotspots.
Live widget for your story
It updates itself while the fire is still active and links to this page. Free, with the attribution shown at the bottom.
Sources for this page: GWIS (Copernicus), NASA FIRMS (VIIRS), ERA5 (ECMWF/Copernicus C3S) · Open-Meteo.com (CC BY 4.0), GHSL (JRC). Open-Meteo.com · How we build fire pages: methodology
- Burnt area
- 3,285ha
- GWIS perimeter (Copernicus)
- Duration
- 20days
- 23 Sept 2025 – 12 Oct 2025
- Municipalities hit
- 1
- municipalities
- Started on
- 23 Sept
- 2025
- Heat detections
- 121
- in a single hotspot: 26 MW
- Danger at start
- 48
- Very high · FWI index
- Average daily power
- 40MW
- detected power per day, on average
Where it burned
HOTSPOTS BY DAY
23 Sept12 Oct
12 Oct 2025
How it evolved, day by day
23 Sept
28 Sept
1 Oct
5 Oct
12 Oct
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
55km/h · peak gust
17%lowest humidity
It had gone more than two months without rain (1 mm or more) when it started. Rain came after the fire: 3.7 mm on 21 Oct.
This area had burned before
65% of the perimeter overlaps earlier fires recorded since 2016: 1,013 ha in 2016, 1,129 ha in 2018, 125 ha in 2019, 133 ha in 2021, 1,129 ha in 2022, 825 ha in 2023, 79 ha in 2024. Part of it burned more than once, so the yearly figures add up to more than the 2,148 ha that had burned before.
- 852 ha Floriano fire, August 2022 4,104 ha in total; the hectares shown are those it shares with this fire
- 120 ha Floriano fire, August 2019 4,842 ha in total; the hectares shown are those it shares with this fire
- 5 ha Itaueira fire, September 2019 3,417 ha in total; the hectares shown are those it shares with this fire
How big is it?
London boundary: geoBoundaries · Office for National Statistics (Open Government Licence v3.0).
Paris boundary: geoBoundaries · Institut national de l'information géographique et forestière (IGN-F) (Etalab Open License 2.0).
Madrid boundary: geoBoundaries · Open Data ESRI, IGN Central Registry of Cartography Area (CC BY 4.0).
Berlin boundary: geoBoundaries · Federal Agency for Cartography and Geodesy (dl-de/by-2-0).
This compares size, not location: both shapes are at the same scale, north up, centred on each other.
What happened to each town
-
3,308 ha reached on 23 Sept1.0 %
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 2025Built-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)
Started with 60 days without rain: 55 % of the area in Brazil
| Day | High | Min. humidity | Peak gust | Rain | Danger (FWI) |
|---|---|---|---|---|---|
| 23 Sept | 38.6 °C | 26 % | 42 km/h | 0.0 mm | Very high 48 |
| 24 Sept | 37.7 °C | 24 % | 44 km/h | 0.0 mm | Extreme 58 |
| 25 Sept | 37.0 °C | 20 % | 53 km/h | 0.0 mm | Extreme 63 |
| 26 Sept | 37.0 °C | 24 % | 50 km/h | 0.0 mm | Extreme 60 |
| 27 Sept | 36.8 °C | 21 % | 53 km/h | 0.0 mm | Extreme 66 |
| 28 Sept | 36.5 °C | 22 % | 52 km/h | 0.0 mm | Extreme 61 |
| 29 Sept | 36.7 °C | 24 % | 48 km/h | 0.0 mm | Extreme 58 |
| 30 Sept | 37.1 °C | 22 % | 50 km/h | 0.0 mm | Extreme 60 |
| 1 Oct | 37.2 °C | 24 % | 48 km/h | 0.0 mm | Extreme 58 |
| 2 Oct | 38.0 °C | 21 % | 47 km/h | 0.0 mm | Extreme 60 |
| 3 Oct | 37.1 °C | 20 % | 52 km/h | 0.0 mm | Extreme 60 |
| 4 Oct | 37.2 °C | 17 % | 55 km/h | 0.0 mm | Very extreme 71 |
| 5 Oct | 37.7 °C | 21 % | 50 km/h | 0.0 mm | Extreme 66 |
| 6 Oct | 38.0 °C | 21 % | 50 km/h | 0.0 mm | Extreme 61 |
| 7 Oct | 38.2 °C | 22 % | 41 km/h | 0.0 mm | Extreme 55 |
| 8 Oct | 39.1 °C | 22 % | 47 km/h | 0.0 mm | Extreme 57 |
| 9 Oct | 38.3 °C | 23 % | 48 km/h | 0.0 mm | Extreme 60 |
| 10 Oct | 38.5 °C | 21 % | 50 km/h | 0.0 mm | Extreme 62 |
| 11 Oct | 38.3 °C | 22 % | 45 km/h | 0.0 mm | Extreme 55 |
| 12 Oct | 38.7 °C | 21 % | 43 km/h | 0.0 mm | Extreme 55 |
| 13 Oct after | 38.1 °C | 25 % | 45 km/h | 0.0 mm | Extreme 55 |
| 14 Oct after | 38.6 °C | 18 % | 35 km/h | 0.0 mm | Extreme 60 |
| 15 Oct after | 38.7 °C | 19 % | 44 km/h | 0.0 mm | Extreme 66 |
| 16 Oct after | 38.4 °C | 16 % | 49 km/h | 0.0 mm | Extreme 66 |
| 17 Oct after | 38.7 °C | 19 % | 46 km/h | 0.0 mm | Extreme 57 |
| 18 Oct after | 38.0 °C | 26 % | 40 km/h | 0.0 mm | Extreme 52 |
| 19 Oct after | 38.2 °C | 29 % | 31 km/h | 0.0 mm | Very high 44 |
| 20 Oct after | 32.8 °C | 45 % | 28 km/h | 0.9 mm | High 28 |
| 21 Oct after | 31.9 °C | 44 % | 55 km/h | 3.7 mm | High 23 |
Its twins: fires that started in the same weather
It started with an FWI of 48.2, a minimum humidity of 26% and more than two months without rain. Fires in the area that started in weather like this since 2016: 59.
FWI at the start
48.2
Minimum humidity
26 %
Days without rain
60+
this fire
chosen twins
rest of the area
Almost identicalSimilar
Outlines of the closest twins
This fire · Floriano fire, 23 September 2025
3,285 ha
20 days
FWI 48.2
Min. humidity 26 %
Santo Inácio do Piauí fire, October 2017
6,631 ha
9 days
FWI 47.8
Min. humidity 26 %
103 km away, in 2017
First rain (1 mm or more) after it ended: 12.5 mm on 31 Oct.
Porto Alegre do Piauí fire, August 2021
3,124 ha
8 days
FWI 48.3
Min. humidity 26 %
118 km away, in 2021
First rain (1 mm or more) after it ended: none in the following ten days.
Oeiras fire, October 2018
3,731 ha
11 days
FWI 46.6
Min. humidity 26 %
70 km away, in 2018
First rain (1 mm or more) after it ended: 1.6 mm on 15 Oct.
Floriano fire, August 2024
10,642 ha
25 days
FWI 49.4
Min. humidity 27 %
48 km away, in 2024
First rain (1 mm or more) after it ended: none in the following ten days.
Brejo do Piauí fire, October 2023
4,543 ha
11 days
FWI 47.8
Min. humidity 25 %
101 km away, in 2023
First rain (1 mm or more) after it ended: 1.4 mm on 2 Nov.
What happened to them
- 16 days
- median duration
- 4,800 ha
- median area
- 15 %
- went past 10,000 ha
- 4.3 mm
- rain at the end (median; 16 of 59 had it)
It burned an area similar to its twins (3,285 ha against a median of 4,800 ha) and lasted 20 days, against 16 days.
In 43 of 59, 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 4.3 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
3.7 mmfirst rain
21 Oct9 days after it ended
55km/h · max. gust
It was considered over on 12 Oct, and on 21 Oct 3.7 mm fell. We do not know whether the rain or the firefighters put it out. Twins with rain when they ended: 16 of 59, with a median of 4.3 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.
Before and after, from space
Drag the line to compare the same ground before the fire and after it.
↔
Before · 16 Sept 2025
After · 19 Oct 2025
Sentinel-2 did not pass over on that day. Try another date, or use false colour, which is daily.
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 · CopernicusOn 6 October 2025 the air beside the fire reached 17 µg/m³ of PM2.5, but no daily average passed the WHO guideline (15).
PM2.5 peak17 µg/m³
Days over the guideline0 days
PM1018 µg/m³
Optical depth0.38
WHO 15
21 Sept25 Sept29 Sept3 Oct7 Oct
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 · 121Every 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
Frequently asked questions
- How long did the Floriano fire last?
- According to the heat detections seen by satellite inside the perimeter, it burned from 23 September 2025 to 12 October 2025 (20 days). The perimeter dates it from 23 September 2025 to 6 October 2025.
- How much area did it burn?
- The perimeter GWIS (Copernicus) rebuilt from heat detections is 3,285 hectares (32.8 km²). It is an estimate: official national figures may differ.
- Which municipalities burned?
- The fire only entered Floriano (3,308 ha, 1.0 %).
- What was the weather like?
- During the fire the temperature reached 39.1 °C, humidity dropped to 17 % and gusts hit 55 km/h. The fire danger index (FWI) reached 71, class Very 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: 59. Their median duration was 16 days and their median area 4,800 ha; 15 % went past 10,000 ha. In 43 of 59, 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 4.3 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.
- Last day with fire: 6 October 2025 → 12 October 2025.
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
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 23 September 2025 to 6 October 2025. 121 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.
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.