Ust-Aldansky Ulus fire, 5 August 2021 Ust-Aldansky Ulus
The fire started on 5 August 2021 in Ust-Aldansky Ulus, Russia, and satellites saw it burning for 11 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 5,361 hectares from heat detections, spread across a single municipality.
It is the 884th largest in Sakha Republic since 2016 (of 1422 with a page). Number 333 in Russia in 2021, of 581.
- Burnt area
- 5,361ha
- GWIS perimeter (Copernicus)
- Duration
- 11days
- 5 Aug 2021 – 15 Aug 2021
- Municipalities hit
- 1
- districts
- Started on
- 5 Aug
- 2021
- Heat detections
- 1,064
- in a single hotspot: 505 MW
- Danger at start
- 30
- High · FWI index
- Energy released
- 16.9GW
- sum of detected power
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 10 days without rain (1 mm or more) when it started. Rain came after the fire: 1.1 mm on 16 Aug.
This area had burned before
11% of the perimeter overlaps earlier fires recorded since 2016: 598 ha in 2017.
What happened to each town
-
Ust-Aldansky Ulus where it started5,317 ha reached on 5 Aug0.3 %
Burnt area inside each municipality, from crossing the GWIS perimeter with administrative boundaries. The distance is from the town centre to the nearest fire: staying a kilometre away does not mean it reached the houses.
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) |
|---|---|---|---|---|---|
| 5 Aug | 26.5 °C | 18 % | 35 km/h | 0.0 mm | High 30 |
| 6 Aug | 26.2 °C | 26 % | 37 km/h | 0.0 mm | High 30 |
| 7 Aug | 26.3 °C | 26 % | 52 km/h | 0.0 mm | High 35 |
| 8 Aug | 26.2 °C | 16 % | 42 km/h | 0.0 mm | High 34 |
| 9 Aug | 28.5 °C | 16 % | 31 km/h | 0.0 mm | High 31 |
| 10 Aug | 29.7 °C | 16 % | 28 km/h | 0.0 mm | High 32 |
| 11 Aug | 28.6 °C | 34 % | 27 km/h | 0.6 mm | High 25 |
| 12 Aug | 23.4 °C | 52 % | 26 km/h | 1.3 mm | Low 9 |
| 13 Aug | 24.3 °C | 49 % | 24 km/h | 0.0 mm | Moderate 13 |
| 14 Aug | 25.3 °C | 50 % | 27 km/h | 3.8 mm | Very low 4 |
| 15 Aug | 22.8 °C | 62 % | 25 km/h | 1.0 mm | Low 6 |
| 16 Aug after | 20.2 °C | 70 % | 30 km/h | 1.1 mm | Very low 4 |
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 · 1,064Every satellite heat detection, one by one, with time, satellite, power and coordinates.
| Date and time | Satellite | FRP (MW) | Lat | Lon |
|---|
Other fires nearby
- 23,004 haUst-Aldansky UlusJune 2021 · 15 days · 11 km away
- 6,757 haUst-Aldansky Ulus31 July 2021 · 14 days · 16 km away
- 11,882 haUst-Aldansky Ulus23 July 2019 · 11 days · 26 km away
- 8,075 haUst-Aldansky Ulus26 July 2019 · 8 days · 27 km away
- 6,200 haUst-Aldansky Ulus8 July 2017 · 8 days · 29 km away
- 85,685 haUst-Aldansky Ulus28 July 2021 · 18 days · 38 km away
Frequently asked questions
- How long did the Ust-Aldansky Ulus fire last?
- GWIS (Copernicus) dates it between 5 August 2021 and 15 August 2021: 11 days between the first and last heat detection of the perimeter.
- How much area did it burn?
- The perimeter GWIS (Copernicus) rebuilt from heat detections is 5,361 hectares (53.6 km²). It is an estimate: official national figures may differ.
- Which municipalities burned?
- The fire only entered Ust-Aldansky Ulus (5,317 ha, 0.3 %).
- What was the weather like?
- During the fire the temperature reached 29.7 °C, humidity dropped to 16 % and gusts hit 52 km/h. The fire danger index (FWI) reached 35, 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
Satellite cross-check
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
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.