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Ust-Maysky Ulus fire, 25 July 2022 Ust-Maysky Ulus

Out · last detection 8 Aug 2022, 16:29 UTC

The fire started on 25 July 2022 in Ust-Maysky Ulus, Russia, and satellites saw it burning for 15 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 31,907 hectares from heat detections, spread across a single municipality.

It is the 130th largest in Sakha Republic since 2016 (of 1347 with a page). Number 13 in Russia in 2022, of 400.

Burnt area
31,907ha
GWIS perimeter (Copernicus)
Duration
15days
25 Jul 2022 – 8 Aug 2022
Municipalities hit
1
districts
Started on
25 Jul
2022
Heat detections
3,607
in a single hotspot: 300 MW
Danger at start
10
Low · FWI index
Average daily power
2.3GW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 25 Jul8 Aug
8 Aug 2022

How it evolved, day by day

25 Jul 2022 · 5 MW · 3 26 Jul 2022 · 310 MW · 17 27 Jul 2022 · 151 MW · 33 28 Jul 2022 · 1,163 MW · 116 29 Jul 2022 · 747 MW · 137 30 Jul 2022 · 997 MW · 223 31 Jul 2022 · 1,065 MW · 210 1 Aug 2022 · 1,867 MW · 136 2 Aug 2022 · 1,345 MW · 63 3 Aug 2022 · 4,854 MW · 549 4 Aug 2022 · 2,556 MW · 585 5 Aug 2022 · 3,855 MW · 764 6 Aug 2022 · 11,551 MW · 563 7 Aug 2022 · 680 MW · 17 8 Aug 2022 · 3,129 MW · 191
25 Jul 28 Jul 31 Jul 3 Aug 6 Aug

Fire radiative power detected each day, in megawatts, and number of hotspots. The magenta bar marks the peak day.

The weather it burned in

31°high
58km/h · peak gust
34%lowest humidity

It had gone one day without rain (1 mm or more) when it started. Rain came after the fire: 11.1 mm on 9 Aug.

This area had burned before

7% of the perimeter overlaps earlier fires recorded since 2016: 2,394 ha in 2018. Part of it burned more than once, so the yearly figures add up to more than the 2,160 ha that had burned before.

How big is it?

10 km
It burned the equivalent of 20% of the area of London (319 km² against 1,583 km²).

London boundary: geoBoundaries · Office for National Statistics (Open Government Licence v3.0).

This compares size, not location: both shapes are at the same scale, north up, centred on each other.

What happened to each town

  1. Ust-Maysky Ulus where it started
    31,504 ha reached on 25 Jul
    0.3 %

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 2020
Built-up area< 0.1 ha
Residents< 20

Inside 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)
25 Jul 25.0 °C 53 % 31 km/h 0.0 mm Low 10
26 Jul 25.0 °C 37 % 31 km/h 0.0 mm Moderate 14
27 Jul 27.8 °C 38 % 14 km/h 0.0 mm Moderate 14
28 Jul 28.7 °C 41 % 20 km/h 0.0 mm Moderate 15
29 Jul 30.6 °C 34 % 17 km/h 0.0 mm Moderate 18
30 Jul 28.7 °C 46 % 30 km/h 0.0 mm Moderate 19
31 Jul 26.0 °C 60 % 31 km/h 6.9 mm Very low 1
1 Aug 29.0 °C 45 % 42 km/h 0.0 mm Low 9
2 Aug 24.8 °C 55 % 45 km/h 10.0 mm Very low 1
3 Aug 26.0 °C 53 % 29 km/h 0.6 mm Very low 4
4 Aug 26.1 °C 44 % 30 km/h 0.0 mm Low 9
5 Aug 25.8 °C 47 % 46 km/h 0.0 mm Moderate 12
6 Aug 23.5 °C 48 % 58 km/h 0.0 mm Moderate 16
7 Aug 20.7 °C 56 % 52 km/h 1.1 mm Low 8
8 Aug 21.6 °C 48 % 42 km/h 0.0 mm Moderate 11
9 Aug after 15.1 °C 67 % 42 km/h 11.1 mm Very low 0

Its twins: fires that started in the same weather

It started with an FWI of 10.3, a minimum humidity of 53% and 1 day without rain. Fires in the area that started in weather like this since 2017: 31.

FWI at the start 10.3
Minimum humidity 53 %
Days without rain 1
this fire chosen twins rest of the area
Almost identicalSimilar

Outlines of the closest twins

Churapchinsky Ulus fire, September 2020
59,025 ha 23 days FWI 9.0 Min. humidity 56 % 178 km away, in 2020

First rain (1 mm or more) after it ended: 1.8 mm on 28 Sept.

What happened to them

15 days
median duration
8,075 ha
median area
42 %
went past 10,000 ha
4.7 mm
rain at the end (median; 29 of 31 had it)

It was 4.0 times larger than the median of its twins and lasted 15 days, against 15 days.

Only 5 of its 31 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 2 of 31, 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 4.7 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

11.1 mmfirst rain
9 Augthe day after it ended
58km/h · max. gust

It was considered over on 8 Aug, and on 9 Aug 11.1 mm fell. We do not know whether the rain or the firefighters put it out. Twins with rain when they ended: 29 of 31, with a median of 4.7 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 2017.
  • 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.

How we calculate it

Before and after, from space

Drag the line to compare the same ground before the fire and after it.

Before · 18 Jul 2022
After · 15 Aug 2022

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 · 3,607Every 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 timeSatelliteFRP (MW)LatLon

Other fires nearby

All fires in Russia

Frequently asked questions

How long did the Ust-Maysky Ulus fire last?
GWIS (Copernicus) dates it between 25 July 2022 and 8 August 2022: 15 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 31,907 hectares (319.1 km²). It is an estimate: official national figures may differ.
Which municipalities burned?
The fire only entered Ust-Maysky Ulus (31,504 ha, 0.3 %).
What was the weather like?
During the fire the temperature reached 30.6 °C, humidity dropped to 34 % and gusts hit 58 km/h. The fire danger index (FWI) reached 19, class Moderate.
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.
How did the fires that started in similar weather in this area end?
Fires less than 250 km away that started since 2017 with a similar FWI, humidity and dry spell: 31. Their median duration was 15 days and their median area 8,075 ha; 42 % went past 10,000 ha. Only 5 of its 31 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 2 of 31, 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 4.7 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: 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.

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
What do you think is wrong?

We will only use your email to reply about this report. Privacy. This is not an emergency service: if there is a fire now, call 112.

How we know this
  • Perimeter: GWIS (Copernicus), rebuilt from heat detections rather than mapped on imagery.
  • Dates from the perimeter: the VIIRS detections inside it did not change them. 3,607 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.

How we build fire pages: methodology

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.