Sarny fire, 21 October 2021 Сарненський район · Sarny
The fire started on 21 October 2021 in Sarny, Ukraine, and satellites saw it burning for 5 days. Copernicus mapped a burnt perimeter of 1,524 hectares from satellite imagery, spread across a single municipality.
It is the 7th largest in Rivne Oblast since 2016 (of 167 with a page). Number 2 in Ukraine in 2021, of 18.
The power measured by the satellite is low (20.8 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: Sarny · 2020Sarny · 2020Sarny · 2020Sarny · 2025
- Burnt area
- 1,524ha
- Copernicus perimeter
- Duration
- 5days
- 21 Oct 2021 – 25 Oct 2021
- Municipalities hit
- 1
- districts
- Started on
- 21 Oct
- 2021
- Heat detections
- 43
- in a single hotspot: 21 MW
- Danger at start
- 8
- Low · FWI index
- Average daily power
- 49MW
- 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 8 days without rain (1 mm or more) when it started. Rain came after the fire: 3.5 mm on 3 Nov.
This area had burned before
58% of the perimeter overlaps earlier fires recorded since 2016: 888 ha in 2020.
- 852 ha Sarny fire, April 2020 1,261 ha in total; the hectares shown are those it shares with this fire
- 24 ha Sarny fire, March 2020 617 ha in total; the hectares shown are those it shares with this fire
- 11 ha Sarny fire, April 2020 1,322 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).
Kyiv boundary: geoBoundaries · OpenStreetMap, Wambacher · © OpenStreetMap contributors (ODbL 1.0).
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).
This compares size, not location: both shapes are at the same scale, north up, centred on each other.
What happened to each town
-
1,525 ha reached on 21 Oct0.7 %
Burnt area inside each municipality, from crossing the official 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.
What burned
- Other natural land60 %
- Mixed forest23 %
- Agricultural areas15 %
- Broadleaved forest2.8 %
Land cover inside the perimeter as reported by Copernicus EFFIS (outside the Corine Land Cover area).
People and buildings inside the perimeter
GHSL 2020Inside the perimeter there were about 0.12 hectares of 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 | Rain | Danger (FWI) |
|---|---|---|---|---|---|
| 21 Oct | 17.7 °C | 47 % | 68 km/h | 0.1 mm | Low 8 |
| 22 Oct | 14.8 °C | 42 % | 55 km/h | 0.0 mm | Low 9 |
| 23 Oct | 9.0 °C | 52 % | 57 km/h | 0.2 mm | Low 9 |
| 24 Oct | 7.6 °C | 56 % | 45 km/h | 0.1 mm | Low 7 |
| 25 Oct | 9.1 °C | 53 % | 25 km/h | 0.0 mm | Low 5 |
| 26 Oct after | 11.2 °C | 49 % | 32 km/h | 0.0 mm | Low 6 |
| 27 Oct after | 11.5 °C | 63 % | 37 km/h | 0.1 mm | Low 6 |
| 28 Oct after | 13.5 °C | 75 % | 42 km/h | 0.0 mm | Very low 5 |
| 29 Oct after | 15.5 °C | 64 % | 35 km/h | 0.0 mm | Very low 5 |
| 30 Oct after | 15.3 °C | 58 % | 35 km/h | 0.0 mm | Low 6 |
| 31 Oct after | 13.3 °C | 60 % | 32 km/h | 0.0 mm | Low 6 |
| 1 Nov after | 11.3 °C | 65 % | 33 km/h | 0.0 mm | Low 5 |
| 2 Nov after | 9.7 °C | 81 % | 33 km/h | 0.0 mm | Very low 4 |
| 3 Nov after | 10.4 °C | 68 % | 42 km/h | 3.5 mm | Very low 0 |
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 28 October 2021 the air beside the fire reached 24 µg/m³ of PM2.5. That day averaged 17: 1.1 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 · 43Every satellite heat detection, one by one, with time, satellite, power and coordinates.
| Date and time | Satellite | FRP (MW) | Lat | Lon |
|---|
Other fires nearby
- 1,560 haSarny Сарненський район13 February 2025 · 5 days · 1 km away
- 2,025 haSarny Сарненський район26 February 2025 · 5 days · 5 km away
- 1,322 haSarny Сарненський район5 April 2020 · 7 days · 5 km away
- 1,703 haSarny Сарненський район21 October 2021 · 11 days · 7 km away
- 1,403 haDubrovytsia Дубровицький район4 March 2025 · 5 days · 12 km away
- 2,260 haDubrovytsia Дубровицький район21 October 2021 · 5 days · 16 km away
Frequently asked questions
- How long did the Sarny fire last?
- Copernicus dates it between 21 October 2021 and 25 October 2021: 5 days between the first and last image with fire.
- How much area did it burn?
- The perimeter Copernicus measured from satellite imagery is 1,524 hectares (15.2 km²). Official national figures may differ.
- Which municipalities burned?
- The fire only entered Sarny (1,525 ha, 0.7 %).
- Did the fire reach a town?
- The fire started in Sarny and came within 34.1 km of its centre. That is the distance from the perimeter, or the nearest hotspot, to the point marking the centre; it does not mean it entered the houses.
- What was the weather like?
- During the fire the temperature reached 17.7 °C, humidity dropped to 42 % and gusts hit 68 km/h. The fire danger index (FWI) reached 9, class Low.
- Where does this data come from?
- From the EFFIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of Ukraine (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: 101 · 112 · Emergency number and official warnings ›
Satellite cross-check
History of this page Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.
No changes since 24 October 2026.
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: EFFIS (Copernicus), mapped on satellite imagery.
- Dates from the perimeter: the VIIRS detections inside it did not change them. 43 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.
Where this data comes from
The perimeter and land cover come from the Copernicus European Forest Fire Information System (EFFIS), measured on MODIS and Sentinel-2 imagery and published under CC BY 4.0. 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 (Public Domain). The area per municipality is computed by WorldFires by crossing the perimeter with those boundaries, so it may differ slightly from each country’s official figure.