Burned area
satellite only16,954ha
Perimeter published by GWIS (Copernicus).
- Source
- GWIS (Copernicus)
- Date
- 4 Oct 2023 – 24 Oct 2023
+− cross-check
No official record is matched to this page to compare it with.
BR · Brazil · –
Formosa do Rio Preto fire, 4 October 2023 Formosa do Rio Preto
Out · last detection 24 Oct 2023, 16:56 UTC
The fire started on 4 October 2023 in Formosa do Rio Preto, Brazil, and satellites saw it burning for 21 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 16,954 hectares from heat detections, spread across a single municipality.
It is the 35th largest in Bahia since 2016 (of 386 with a page). Number 20 in Brazil in 2023, of 430.
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 only21days
4 Oct 2023 to 24 Oct 2023: first and last day with fire on the page.
- Source
- GWIS (Copernicus) · NASA FIRMS · VIIRS
- Date
- last detection: 24 Oct 2023, 16:56 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 only4 Oct 2023
First day with fire seen by the satellites or the perimeter.
- Source
- GWIS (Copernicus) · NASA FIRMS · VIIRS
- Date
- 4 Oct 2023
+− cross-check
No official record is matched to this page, so the alert time and the cause are not known here.
Hotspots
satellite only673
VIIRS detections at 375 m. Most intense hotspot: 163 MW.
- Source
- NASA FIRMS · VIIRS (Suomi NPP)
- Date
- 4 Oct 2023 – 24 Oct 2023
+− 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 only1,656MW
Total radiative power on 17 October 2023; hotspots that day: 94.
- Source
- NASA FIRMS · VIIRS (FRP)
- Date
- 17 Oct 2023
+− 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
model56.0FWI · extreme
Fire Weather Index (Canadian system) computed by WorldFires for the day the fire started. Consecutive days without rain before: 35.
- Source
- WorldFires calculation (Canadian FWI system)
- Date
- 4 Oct 2023, 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
model37.5°C · 19% RH
High of 37.5 °C and minimum humidity of 19% on 19 October 2023; gusts of 38 km/h on 16 October 2023.
- Source
- weather model at the fire’s grid cell
- Date
- 4 Oct 2023 – 24 Oct 2023
- 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.
Living inside
model≈ 150people
Estimated residents inside the perimeter and 1.7 ha of built-up area (100 m grid, epoch 2025).
- Source
- GHSL R2023A · JRC
- Date
- calculated on 24 October 2026
+− cross-check
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.
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: 22 October 2023 → 24 October 2023.
-
logStart date: 10 October 2023 → 4 October 2023.
-
· 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
- 16,954 ha
- Dates
- 4 Oct 2023 – 24 Oct 2023
- Name
- Formosa do Rio Preto
- Official record
- —
Versioned permanent link
https://worldfires.org/en/fire/formosa-do-rio-preto-2023-10?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 formosa-do-rio-preto-2023-10.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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 2023-10-04 | 3 | 5 | 36.8 | 22.7 | 24 | 15.3 | 34.2 | 0 | 56 | extremo | 1 |
| 2023-10-05 | 0 | 0 | 36.3 | 23.7 | 30 | 13.7 | 34.2 | 0 | 52.9 | extremo | 1 |
| 2023-10-06 | 0 | 0 | 35.3 | 24.7 | 34 | 15.7 | 37.4 | 0.1 | 50.2 | extremo | 1 |
| 2023-10-07 | 0 | 0 | 36.1 | 23.2 | 31 | 10.7 | 28.1 | 0 | 46.1 | muy_alto | 1 |
| 2023-10-08 | 0 | 0 | 36.4 | 24.3 | 30 | 15.4 | 37.1 | 0 | 47.9 | muy_alto | 1 |
| 2023-10-09 | 1 | 5 | 37.1 | 23.8 | 28 | 8.7 | 24.8 | 0 | 42.1 | muy_alto | 1 |
| 2023-10-10 | 4 | 44 | 37.4 | 24 | 26 | 15 | 35.3 | 0 | 46.3 | muy_alto | 1 |
| 2023-10-11 | 48 | 259 | 35.6 | 24.8 | 28 | 15.5 | 35.3 | 0 | 44.5 | muy_alto | 1 |
| 2023-10-12 | 8 | 66 | 36.5 | 21.3 | 21 | 11.4 | 28.4 | 0 | 40.5 | muy_alto | 1 |
| 2023-10-13 | 4 | 22 | 37 | 22.8 | 28 | 8 | 22 | 0.1 | 36 | alto | 1 |
| 2023-10-14 | 10 | 83 | 36.3 | 23.8 | 29 | 12.8 | 32 | 0 | 39.4 | muy_alto | 1 |
| 2023-10-15 | 60 | 849 | 35.6 | 24.5 | 25 | 18 | 36.4 | 0 | 49.7 | muy_alto | 1 |
| 2023-10-16 | 68 | 920 | 35.4 | 22.7 | 19 | 17.9 | 38.2 | 0 | 51.4 | extremo | 1 |
| 2023-10-17 | 94 | 1,656 | 35.4 | 21.6 | 20 | 15.5 | 34.9 | 0 | 50.8 | extremo | 1 |
| 2023-10-18 | 80 | 1,186 | 36.4 | 20.4 | 19 | 13.8 | 33.8 | 0 | 49.6 | muy_alto | 1 |
| 2023-10-19 | 122 | 1,117 | 37.5 | 20.3 | 19 | 12 | 28.8 | 0 | 47.1 | muy_alto | 1 |
| 2023-10-20 | 84 | 367 | 37.2 | 22.4 | 22 | 14.2 | 33.1 | 0 | 50.3 | extremo | 1 |
| 2023-10-21 | 74 | 1,151 | 36.7 | 24.4 | 27 | 15.2 | 35.6 | 0 | 50.1 | extremo | 1 |
| 2023-10-22 | 12 | 114 | 35.4 | 24.9 | 29 | 16.4 | 37.1 | 0 | 51.4 | extremo | 1 |
| 2023-10-23 | 0 | 0 | 36 | 25.7 | 28 | 17.9 | 37.8 | 0 | 52.3 | extremo | 1 |
| 2023-10-24 | 1 | 11 | 36.7 | 24.2 | 28 | 10.5 | 28.4 | 0 | 45.5 | muy_alto | 1 |
| 2023-10-25 | 0 | 0 | 31.8 | 24.5 | 43 | 8.1 | 22.7 | 0.1 | 28.7 | alto | 0 |
| 2023-10-26 | 0 | 0 | 31.7 | 23.8 | 48 | 11.4 | 32.4 | 2.5 | 30.9 | 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
- 16,954ha
- GWIS perimeter (Copernicus)
- Duration
- 21days
- 4 Oct 2023 – 24 Oct 2023
- Municipalities hit
- 1
- municipalities
- Started on
- 4 Oct
- 2023
- Heat detections
- 673
- in a single hotspot: 163 MW
- Danger at start
- 56
- Extreme · FWI index
- Average daily power
- 491MW
- detected power per day, on average
Where it burned
HOTSPOTS BY DAY
4 Oct24 Oct
24 Oct 2023
How it evolved, day by day
4 Oct
12 Oct
17 Oct
20 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
38°high
38km/h · peak gust
19%lowest humidity
It had gone 35 days without rain (1 mm or more) when it started. Rain came after the fire: 2.5 mm on 26 Oct.
This area had burned before
69% of the perimeter overlaps earlier fires recorded since 2016: 2,264 ha in 2019, 10,387 ha in 2021, 267 ha in 2022. Part of it burned more than once, so the yearly figures add up to more than the 11,689 ha that had burned before.
- 9,839 ha Formosa do Rio Preto fire, August 2021 17,184 ha in total; the hectares shown are those it shares with this fire
- 2,264 ha Formosa do Rio Preto fire, September 2019 6,942 ha in total; the hectares shown are those it shares with this fire
- 267 ha Formosa do Rio Preto fire, October 2022 4,880 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
-
17,082 ha reached on 4 Oct1.1 %
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 2025Built-up area1.7 ha
Residents≈ 150
Inside the perimeter there were about 1.7 hectares of built-up land and about 150 residents (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 Extreme FWI: 46 % of the area in Brazil
| Day | High | Min. humidity | Peak gust | Rain | Danger (FWI) |
|---|---|---|---|---|---|
| 4 Oct | 36.8 °C | 24 % | 34 km/h | 0.0 mm | Extreme 56 |
| 5 Oct | 36.3 °C | 30 % | 34 km/h | 0.0 mm | Extreme 53 |
| 6 Oct | 35.3 °C | 34 % | 37 km/h | 0.1 mm | Extreme 50 |
| 7 Oct | 36.1 °C | 31 % | 28 km/h | 0.0 mm | Very high 46 |
| 8 Oct | 36.4 °C | 30 % | 37 km/h | 0.0 mm | Very high 48 |
| 9 Oct | 37.1 °C | 28 % | 25 km/h | 0.0 mm | Very high 42 |
| 10 Oct | 37.4 °C | 26 % | 35 km/h | 0.0 mm | Very high 46 |
| 11 Oct | 35.6 °C | 28 % | 35 km/h | 0.0 mm | Very high 44 |
| 12 Oct | 36.5 °C | 21 % | 28 km/h | 0.0 mm | Very high 40 |
| 13 Oct | 37.0 °C | 28 % | 22 km/h | 0.1 mm | High 36 |
| 14 Oct | 36.3 °C | 29 % | 32 km/h | 0.0 mm | Very high 39 |
| 15 Oct | 35.6 °C | 25 % | 36 km/h | 0.0 mm | Very high 50 |
| 16 Oct | 35.4 °C | 19 % | 38 km/h | 0.0 mm | Extreme 51 |
| 17 Oct | 35.4 °C | 20 % | 35 km/h | 0.0 mm | Extreme 51 |
| 18 Oct | 36.4 °C | 19 % | 34 km/h | 0.0 mm | Very high 50 |
| 19 Oct | 37.5 °C | 19 % | 29 km/h | 0.0 mm | Very high 47 |
| 20 Oct | 37.2 °C | 22 % | 33 km/h | 0.0 mm | Extreme 50 |
| 21 Oct | 36.7 °C | 27 % | 36 km/h | 0.0 mm | Extreme 50 |
| 22 Oct | 35.4 °C | 29 % | 37 km/h | 0.0 mm | Extreme 51 |
| 23 Oct | 36.0 °C | 28 % | 38 km/h | 0.0 mm | Extreme 52 |
| 24 Oct | 36.7 °C | 28 % | 28 km/h | 0.0 mm | Very high 46 |
| 25 Oct after | 31.8 °C | 43 % | 23 km/h | 0.1 mm | High 29 |
| 26 Oct after | 31.7 °C | 48 % | 32 km/h | 2.5 mm | High 31 |
Its twins: fires that started in the same weather
It started with an FWI of 56.0, a minimum humidity of 24% and 35 days without rain. Fires in the area that started in weather like this since 2016: 77.
FWI at the start
56.0
Minimum humidity
24 %
Days without rain
35
this fire
chosen twins
rest of the area
Almost identicalSimilar
Outlines of the closest twins
This fire · Formosa do Rio Preto fire, 4 October 2023
16,954 ha
21 days
FWI 56.0
Min. humidity 24 %
Almas fire, September 2018
5,924 ha
9 days
FWI 55.1
Min. humidity 24 %
249 km away, in 2018
First rain (1 mm or more) after it ended: 15.1 mm on 1 Oct.
Mansidão fire, September 2018
21,838 ha
26 days
FWI 50.3
Min. humidity 24 %
109 km away, in 2018
First rain (1 mm or more) after it ended: 1.3 mm on 15 Oct.
Formosa do Rio Preto fire, September 2023
4,251 ha
5 days
FWI 58.2
Min. humidity 24 %
66 km away, in 2023
First rain (1 mm or more) after it ended: 2.9 mm on 27 Sept.
Júlio Borges fire, August 2019
6,616 ha
15 days
FWI 52.1
Min. humidity 24 %
149 km away, in 2019
First rain (1 mm or more) after it ended: none in the following ten days.
Riachão das Neves fire, September 2025
11,049 ha
17 days
FWI 55.3
Min. humidity 23 %
53 km away, in 2025
First rain (1 mm or more) after it ended: 7.6 mm on 20 Oct.
What happened to them
- 12 days
- median duration
- 5,153 ha
- median area
- 25 %
- went past 10,000 ha
- 5.8 mm
- rain at the end (median; 27 of 77 had it)
It was 3.3 times larger than the median of its twins and lasted 21 days, against 12 days.
Only 3 of its 77 twins burned more. The weather on the first day does not explain everything: the wind in the following days, the fuel and the firefighting also count. In 50 of 77, 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 5.8 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
2.5 mmfirst rain
26 Oct2 days after it ended
38km/h · max. gust
It was considered over on 24 Oct, and on 26 Oct 2.5 mm fell. We do not know whether the rain or the firefighters put it out. Twins with rain when they ended: 27 of 77, with a median of 5.8 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 · 27 Sept 2023
After · 31 Oct 2023
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 19 October 2023 the air beside the fire reached 19 µg/m³ of PM2.5, but no daily average passed the WHO guideline (15).
PM2.5 peak19 µg/m³
Days over the guideline0 days
PM1027 µg/m³
Optical depth0.55
WHO 15
8 Oct12 Oct16 Oct20 Oct24 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 · 673Every 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
- 29,004 haRiachão das Neves19 August 2026 · 28 days · 6 km away
- 17,667 haFormosa do Rio Preto27 September 2026 · 16 days · 12 km away
- 32,000 haRiachão das Neves22 September 2025 · 18 days · 22 km away
- 19,616 haRiachão das Neves5 September 2021 · 32 days · 23 km away
- 17,607 haFormosa do Rio Preto14 September 2021 · 27 days · 24 km away
Frequently asked questions
- How long did the Formosa do Rio Preto fire last?
- According to the heat detections seen by satellite inside the perimeter, it burned from 4 October 2023 to 24 October 2023 (21 days). The perimeter dates it from 10 October 2023 to 22 October 2023.
- How much area did it burn?
- The perimeter GWIS (Copernicus) rebuilt from heat detections is 16,954 hectares (169.5 km²). It is an estimate: official national figures may differ.
- Which municipalities burned?
- The fire only entered Formosa do Rio Preto (17,082 ha, 1.1 %).
- What was the weather like?
- During the fire the temperature reached 37.5 °C, humidity dropped to 19 % and gusts hit 38 km/h. The fire danger index (FWI) reached 56, 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.
- 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: 77. Their median duration was 12 days and their median area 5,153 ha; 25 % went past 10,000 ha. Only 3 of its 77 twins burned more. The weather on the first day does not explain everything: the wind in the following days, the fuel and the firefighting also count. In 50 of 77, 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 5.8 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 · 2 Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.
- Last day with fire: 22 October 2023 → 24 October 2023.
- Start date: 10 October 2023 → 4 October 2023.
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 10 October 2023 to 22 October 2023. 673 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.