Ust-Aldansky Ulus fire, 21 July 2020 Ust-Aldansky Ulus, Kobyaysky Ulus
The fire started on 21 July 2020 in Ust-Aldansky Ulus, Russia, and satellites saw it burning for 47 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 65,488 hectares from heat detections, spread across 2 municipalities.
This page is probably a fire complex, not a single fire. GWIS merges into one perimeter the fires that touch over weeks, which in large burning seasons can join dozens of separate fires. The total area is reliable; the origin and dates refer to the whole complex.
Other fire pages in the same area and on the same dates:
It is the 59th largest in Sakha Republic since 2016 (of 1422 with a page). Number 12 in Russia in 2020, of 592.
Compare with…
- Burnt area
- 65,488ha
- GWIS perimeter (Copernicus)
- Duration
- 47days
- 21 Jul 2020 – 5 Sept 2020
- Municipalities hit
- 2
- districts
- Started on
- 21 Jul
- 2020
- Heat detections
- 8,764
- in a single hotspot: 353 MW
- Danger at start
- 26
- High · FWI index
- Average daily power
- 2.4GW
- 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. Rain came after the fire: 1.6 mm on 13 Sept.
This area had burned before
1% of the perimeter overlaps earlier fires recorded since 2016: 984 ha in 2017.
- 386 ha Kobyaysky Ulus fire, July 2017 5,679 ha in total; the hectares shown are those it shares with this fire
- 330 ha Ust-Aldansky Ulus fire, June 2017 23,725 ha in total; the hectares shown are those it shares with this fire
- 136 ha Ust-Aldansky Ulus fire, June 2017 8,686 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).
Moscow 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
-
Ust-Aldansky Ulus where it started66,424 ha reached on 21 Jul3.6 %
-
67 ha reached on 23 Aug0.0 %
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 2020Inside 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 | Rain | Danger (FWI) |
|---|---|---|---|---|---|
| 21 Jul | 27.0 °C | 42 % | 58 km/h | 0.0 mm | High 26 |
| 22 Jul | 21.8 °C | 47 % | 52 km/h | 0.0 mm | High 24 |
| 23 Jul | 25.0 °C | 41 % | 38 km/h | 0.0 mm | Moderate 20 |
| 24 Jul | 29.0 °C | 33 % | 27 km/h | 0.0 mm | High 22 |
| 25 Jul | 30.2 °C | 29 % | 38 km/h | 2.3 mm | Moderate 15 |
| 26 Jul | 23.7 °C | 41 % | 37 km/h | 10.9 mm | Very low 3 |
| 27 Jul | 26.4 °C | 33 % | 25 km/h | 0.0 mm | Low 8 |
| 28 Jul | 25.9 °C | 37 % | 31 km/h | 0.1 mm | Moderate 15 |
| 29 Jul | 23.4 °C | 37 % | 26 km/h | 0.0 mm | Moderate 17 |
| 30 Jul | 24.6 °C | 30 % | 27 km/h | 0.0 mm | Moderate 20 |
| 31 Jul | 25.4 °C | 28 % | 22 km/h | 0.0 mm | Moderate 21 |
| 1 Aug | 26.8 °C | 25 % | 21 km/h | 0.0 mm | High 23 |
| 2 Aug | 26.8 °C | 29 % | 20 km/h | 0.0 mm | High 23 |
| 3 Aug | 25.9 °C | 35 % | 19 km/h | 0.0 mm | High 23 |
| 4 Aug | 26.1 °C | 33 % | 19 km/h | 0.3 mm | High 22 |
| 5 Aug | 25.3 °C | 33 % | 19 km/h | 0.0 mm | High 22 |
| 6 Aug | 25.2 °C | 34 % | 16 km/h | 0.0 mm | High 22 |
| 7 Aug | 25.2 °C | 35 % | 17 km/h | 0.0 mm | High 22 |
| 8 Aug | 25.5 °C | 33 % | 18 km/h | 0.0 mm | High 23 |
| 9 Aug | 25.4 °C | 43 % | 37 km/h | 0.4 mm | High 24 |
| 10 Aug | 18.6 °C | 69 % | 22 km/h | 7.6 mm | Very low 0 |
| 11 Aug | 20.4 °C | 45 % | 20 km/h | 1.1 mm | Very low 3 |
| 12 Aug | 19.9 °C | 50 % | 37 km/h | 0.0 mm | Low 8 |
| 13 Aug | 13.3 °C | 35 % | 66 km/h | 0.7 mm | Moderate 17 |
| 14 Aug | 16.2 °C | 40 % | 34 km/h | 0.0 mm | Moderate 14 |
| 15 Aug | 17.9 °C | 35 % | 20 km/h | 0.0 mm | Moderate 15 |
| 16 Aug | 16.1 °C | 50 % | 21 km/h | 0.3 mm | Moderate 14 |
| 17 Aug | 18.3 °C | 31 % | 26 km/h | 0.0 mm | Moderate 17 |
| 18 Aug | 20.3 °C | 28 % | 20 km/h | 0.0 mm | Moderate 19 |
| 19 Aug | 19.2 °C | 36 % | 23 km/h | 0.0 mm | Moderate 20 |
| 20 Aug | 18.2 °C | 30 % | 30 km/h | 0.0 mm | High 22 |
| 21 Aug | 18.2 °C | 33 % | 22 km/h | 0.0 mm | Moderate 21 |
| 22 Aug | 17.6 °C | 27 % | 27 km/h | 0.0 mm | High 22 |
| 23 Aug | 16.2 °C | 30 % | 22 km/h | 0.0 mm | High 22 |
| 24 Aug | 9.8 °C | 56 % | 32 km/h | 5.8 mm | Very low 1 |
| 25 Aug | 15.0 °C | 38 % | 22 km/h | 0.0 mm | Very low 4 |
| 26 Aug | 17.6 °C | 33 % | 17 km/h | 0.0 mm | Low 8 |
| 27 Aug | 19.4 °C | 27 % | 22 km/h | 0.0 mm | Moderate 15 |
| 28 Aug | 20.2 °C | 20 % | 22 km/h | 0.0 mm | Moderate 19 |
| 29 Aug | 20.4 °C | 33 % | 23 km/h | 0.0 mm | High 22 |
| 30 Aug | 14.8 °C | 44 % | 38 km/h | 1.4 mm | Low 9 |
| 31 Aug | 12.6 °C | 76 % | 26 km/h | 0.8 mm | Low 6 |
| 1 Sept | 15.8 °C | 58 % | 17 km/h | 0.1 mm | Low 7 |
| 2 Sept | 15.2 °C | 60 % | 22 km/h | 3.6 mm | Very low 1 |
| 3 Sept | 16.7 °C | 58 % | 28 km/h | 0.3 mm | Very low 5 |
| 4 Sept | 20.7 °C | 43 % | 39 km/h | 0.0 mm | Low 11 |
| 5 Sept | 20.9 °C | 38 % | 25 km/h | 0.0 mm | Moderate 14 |
| 6 Sept after | 19.2 °C | 50 % | 18 km/h | 0.6 mm | Low 10 |
| 7 Sept after | 17.0 °C | 42 % | 25 km/h | 0.6 mm | Moderate 12 |
| 8 Sept after | 16.1 °C | 38 % | 20 km/h | 0.0 mm | Moderate 13 |
| 9 Sept after | 17.1 °C | 38 % | 21 km/h | 0.0 mm | Moderate 14 |
| 10 Sept after | 17.5 °C | 37 % | 19 km/h | 0.0 mm | Moderate 15 |
| 11 Sept after | 19.1 °C | 31 % | 26 km/h | 0.0 mm | Moderate 19 |
| 12 Sept after | 16.7 °C | 44 % | 26 km/h | 0.1 mm | Moderate 18 |
| 13 Sept after | 18.9 °C | 34 % | 34 km/h | 1.6 mm | Low 10 |
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.
Detections table · 8,764Every satellite heat detection, one by one, with time, satellite, power and coordinates.
| Date and time | Satellite | FRP (MW) | Lat | Lon |
|---|
Other fires nearby
- 5,679 haKobyaysky UlusJuly 2017 · 11 days · 12 km away
- 8,686 haUst-Aldansky Ulus26 June 2017 · 20 days · 13 km away
- 5,909 haUst-Aldansky Ulus3 July 2017 · 13 days · 24 km away
- 5,696 haUst-Aldansky Ulus4 September 2020 · 22 days · 25 km away
- 4,297 haKobyaysky UlusSeptember 2020 · 17 days · 28 km away
- 49,070 haKobyaysky Ulus21 July 2019 · 19 days · 32 km away
Frequently asked questions
- How long did the Ust-Aldansky Ulus fire last?
- According to the heat detections seen by satellite inside the perimeter, it burned from 21 July 2020 to 5 September 2020 (47 days). The perimeter dates it from 28 July 2020 to 29 August 2020.
- How much area did it burn?
- The perimeter GWIS (Copernicus) rebuilt from heat detections is 65,488 hectares (654.9 km²). It is an estimate: official national figures may differ.
- Which municipalities burned?
- The fire entered 2 municipalities: Ust-Aldansky Ulus (66,424 ha, 3.6 %); Kobyaysky Ulus (67 ha, 0.0 %).
- What was the weather like?
- During the fire the temperature reached 30.2 °C, humidity dropped to 20 % and gusts hit 66 km/h. The fire danger index (FWI) reached 26, class High.
- Where does this data come from?
- From the GWIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of Russia (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: 112 · 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: 29 August 2020 → 5 September 2020.
- Start date: 28 July 2020 → 21 July 2020.
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; 2 polygons grouped in this page.
- Dates adjusted with the VIIRS detections inside the perimeter, which said 28 July 2020 to 29 August 2020. 8,764 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 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 (Open Data Commons Open Database License 1.0). 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.