Isaac fire, 25 September 2025 Isaac
The fire started on 25 September 2025 in Isaac, Australia, and satellites saw it burning for 21 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 17,876 hectares from heat detections, spread across a single municipality.
It is the 359th largest in Queensland since 2016 (of 1743 with a page). Number 236 in Australia in 2025, of 1124.
Compare with…
Suggestions: Isaac · 2017Isaac · 2020Isaac · 2025Isaac · 2025
- Burnt area
- 17,876ha
- GWIS perimeter (Copernicus)
- Duration
- 21days
- 25 Sept 2025 – 15 Oct 2025
- Municipalities hit
- 1
- local government areas
- Started on
- 25 Sept
- 2025
- Heat detections
- 652
- in a single hotspot: 84 MW
- Danger at start
- 17
- Moderate · FWI index
- Average daily power
- 232MW
- detected power per day, on average
Where it burned
How it evolved, day by day
Fire radiative power detected each day, in megawatts, and number of hotspots. The magenta bar marks the peak day.
The weather it burned in
It had gone 2 days without rain (1 mm or more) when it started.
This area had burned before
79% of the perimeter overlaps earlier fires recorded since 2016: 4,631 ha in 2016, 4,470 ha in 2017, 177 ha in 2019, 2,852 ha in 2020, 1,770 ha in 2021, 7,372 ha in 2022, 622 ha in 2023, 2,325 ha in 2024. Part of it burned more than once, so the yearly figures add up to more than the 14,152 ha that had burned before.
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
-
Isaac where it started17,935 ha reached on 25 Sept0.3 %
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 2025Inside the perimeter there were about 0.13 hectares of 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) |
|---|---|---|---|---|---|
| 25 Sept | 24.7 °C | 31 % | 28 km/h | 0.0 mm | Moderate 17 |
| 26 Sept | 24.5 °C | 35 % | 38 km/h | 0.0 mm | Moderate 20 |
| 27 Sept | 23.7 °C | 47 % | 42 km/h | 0.0 mm | Moderate 20 |
| 28 Sept | 26.4 °C | 49 % | 35 km/h | 0.4 mm | Moderate 17 |
| 29 Sept | 29.4 °C | 28 % | 27 km/h | 0.0 mm | High 22 |
| 30 Sept | 27.6 °C | 39 % | 29 km/h | 0.0 mm | High 22 |
| 1 Oct | 29.8 °C | 39 % | 29 km/h | 0.0 mm | Moderate 21 |
| 2 Oct | 33.8 °C | 26 % | 30 km/h | 0.0 mm | High 27 |
| 3 Oct | 29.2 °C | 16 % | 39 km/h | 0.0 mm | High 34 |
| 4 Oct | 26.1 °C | 33 % | 37 km/h | 0.0 mm | High 28 |
| 5 Oct | 23.9 °C | 45 % | 52 km/h | 0.0 mm | High 26 |
| 6 Oct | 24.4 °C | 45 % | 37 km/h | 0.0 mm | Moderate 21 |
| 7 Oct | 26.2 °C | 42 % | 38 km/h | 0.0 mm | High 22 |
| 8 Oct | 26.3 °C | 47 % | 39 km/h | 0.0 mm | High 23 |
| 9 Oct | 27.9 °C | 50 % | 41 km/h | 0.7 mm | Moderate 18 |
| 10 Oct | 26.6 °C | 46 % | 37 km/h | 0.0 mm | Moderate 19 |
| 11 Oct | 27.8 °C | 50 % | 36 km/h | 0.2 mm | Moderate 19 |
| 12 Oct | 29.0 °C | 45 % | 39 km/h | 0.0 mm | Moderate 21 |
| 13 Oct | 28.4 °C | 53 % | 32 km/h | 1.4 mm | Low 10 |
| 14 Oct | 28.2 °C | 47 % | 44 km/h | 0.0 mm | Moderate 20 |
| 15 Oct | 27.1 °C | 48 % | 49 km/h | 0.0 mm | High 22 |
| 16 Oct after | 25.0 °C | 46 % | 49 km/h | 0.0 mm | High 22 |
| 17 Oct after | 25.8 °C | 47 % | 39 km/h | 0.0 mm | Moderate 20 |
| 18 Oct after | 27.9 °C | 39 % | 34 km/h | 0.0 mm | High 22 |
| 19 Oct after | 27.9 °C | 43 % | 37 km/h | 0.0 mm | High 23 |
| 20 Oct after | 27.6 °C | 44 % | 36 km/h | 0.0 mm | High 23 |
| 21 Oct after | 27.4 °C | 35 % | 39 km/h | 0.0 mm | High 25 |
| 22 Oct after | 28.5 °C | 43 % | 35 km/h | 0.0 mm | High 26 |
| 23 Oct after | 31.8 °C | 37 % | 33 km/h | 0.0 mm | High 26 |
| 24 Oct after | 31.9 °C | 38 % | 41 km/h | 0.0 mm | High 29 |
| 25 Oct after | 31.4 °C | 42 % | 39 km/h | 0.1 mm | High 29 |
Before and after, from space
Drag the line to compare the same ground before the fire and after it.
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 26 September 2025 the air beside the fire reached 52 µg/m³ of PM2.5. That day averaged 26: 1.7 times the WHO daily guideline (15).
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 · 652Every satellite heat detection, one by one, with time, satellite, power and coordinates.
| Date and time | Satellite | FRP (MW) | Lat | Lon |
|---|
Other fires nearby
- 8,287 haIsaacDecember 2017 · 14 days · 17 km away
- 5,336 haIsaac4 November 2020 · 22 days · 21 km away
- 5,081 haIsaac20 November 2025 · 7 days · 22 km away
- 12,425 haIsaac14 September 2025 · 25 days · 23 km away
- 5,090 haIsaacOctober 2021 · 6 days · 25 km away
- 8,672 haIsaacDecember 2019 · 8 days · 26 km away
Frequently asked questions
- How long did the Isaac fire last?
- According to the heat detections seen by satellite inside the perimeter, it burned from 25 September 2025 to 15 October 2025 (21 days). The perimeter dates it from 25 September 2025 to 14 October 2025.
- How much area did it burn?
- The perimeter GWIS (Copernicus) rebuilt from heat detections is 17,876 hectares (178.8 km²). It is an estimate: official national figures may differ.
- Which municipalities burned?
- The fire only entered Isaac (17,935 ha, 0.3 %).
- What was the weather like?
- During the fire the temperature reached 33.8 °C, humidity dropped to 16 % and gusts hit 52 km/h. The fire danger index (FWI) reached 34, class High.
- Where does this data come from?
- From the GWIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of Australia (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: 000 · 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: 14 October 2025 → 15 October 2025.
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 25 September 2025 to 14 October 2025. 652 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 4.0 International (CC BY 4.0)). 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.