Ust’-Kut weather in September

In September, Ust’-Kut sees average daytime highs of 12°C and overnight lows near 2°C, with 51 mm of precipitation across 11.2 wet days and about 12.5 hours of daylight. It is the 5th-warmest and 4th-wettest month of the year here.

Highs ease over the month, from about 16°C in the first days to 8°C by the end. The sky is clear or mostly clear about 15% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 h 42 min at the start of September to 11 h 18 min by month's end. Set against the rest of the year, September is Ust’-Kut's 4th-clearest and 7th-windiest month. For the whole year in context, see Ust’-Kut's year-round climate.

Daytime high
12°
5th warmest
Overnight low
9th coldest
Precipitation
51 mm
11.2 wet days
Daylight
12 h 30 min
6:37 AM – 7:05 PM
Cloud cover
72%
4th clearest
Wind
9 km/h
7th windiest
Solar energy
2.86 kWh/m²
Travel score
2.9
out of 10

Ust’-Kut is human settlement in Ust-Kutsky District, Irkutsk Oblast, Russia.

Density
861/km²
people per km²
Founded
1631

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 16°C in the first days to 8°C by the end.

A typical September day in Ust’-Kut reaches about 12°C in the afternoon and slips back to 2°C overnight — a 10°C spread between the day's warmth and the night's chill. On most days the high lands between 6°C and 18°C. Set against its neighbours, September runs about 9°C cooler than August and about 10°C warmer than October.

-10°10°20°151015202530
Avg high (°C)Avg low (°C)
1166
2166
3165
4155
5155
6154
7144
8144
9144
10133
11133
12133
13133
14122
15122
16122
17112
18111
19111
20101
21100
22100
2390
2490
2590
268-1
278-1
288-1
297-1
307-2

How September really feels in Ust’-Kut

Once humidity and wind are folded in, September averages 0 days that feel above 32°C and 17 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
0
heat index over the day's high
Days feeling ≤ C
17
wind chill below the day's low

The story in September is cold — wind chill drags the overnight "feels like" below the raw low.

Ust’-Kut weather by month

How September compares with the rest of the year at a glance. September is the 5th-warmest and 4th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan-20° / -28°134.78.67.20.0
Feb-14° / -24°113.879.10.0
Mar-4° / -16°186.28.611.40.0
Apr / -7°289713.90.4
May14° / 4411.72.116.13.6
Jun21° / 5711.8017.46.0
Jul23° / 12°6911.4016.96.6
Aug20° / 7211.3014.96.0
Sep12° / 5111.21.312.52.9
Oct / -6°3710.48.9100.1
Nov-11° / -19°278.611.47.80.0
Dec-18° / -26°186.610.26.60.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 15% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 9% of September, with mostly cloudy or overcast conditions the remaining 76%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
12872
22872
32773
42674
52674
62674
72674
82674
92575
102575
112476
122476
132476
142377
152377
162476
172476
182476
192476
202575
212476
222476
232377
242377
252377
262377
272377
282278
292278
302179

Chance of precipitation in September

Any precipitationSnow

Ust’-Kut gets around 51 mm of rain and snow over 11.2 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 37% and peaks near 40% on the wettest days, and about 1 day brings snow.

0%10%20%30%40%50%151015202530
Rain chance (%)Snow chance (%)
1400
2401
3401
4401
5391
6391
7391
8392
9392
10382
11382
12383
13373
14373
15363
16364
17364
18364
19365
20355
21356
22356
23357
24358
25358
26359
273510
283511
293612
303614

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

Most of September feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, September lands in the dry band about 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)
1973
2982
3982
4991
5991
6991
7991
81000
91000
101000
111000
121000
131000
141000
151000
161000
171000
181000
191000
201000
211000
221000
231000
241000
251000
261000
271000
281000
291000
301000

Wind in September

Winds average 9 km/h in September.

Across September, daily wind ranges from about 8 km/h on the calmest days to 9 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
18calm
28calm
38calm
48calm
58calm
68calm
78calm
89calm
99calm
109calm
119calm
129calm
139calm
149calm
159calm
169calm
179calm
189calm
199calm
209calm
219calm
229calm
239calm
249calm
259calm
269calm
279calm
289calm
299calm
309calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 h 42 min at the start of September to 11 h 18 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 144 minutes over September. Sunrise moves from 6:06 AM to 7:06 AM, and sunset from 7:47 PM to 6:26 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.76:067:47
213.66:087:45
313.56:107:42
413.56:127:39
513.46:147:36
613.36:167:34
713.26:187:31
813.16:207:28
913.06:227:25
1013.06:247:22
1112.96:277:20
1212.86:297:17
1312.76:317:14
1412.66:337:11
1512.66:357:08
1612.56:377:05
1712.46:397:03
1812.36:417:00
1912.26:436:57
2012.16:456:54
2112.16:476:51
2212.06:506:48
2311.96:526:46
2411.86:546:43
2511.76:566:40
2611.76:586:37
2711.67:006:34
2811.57:026:31
2911.47:046:29
3011.37:066:26

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 2.86 kWh/m².

For context, solar energy here swings from a low near 0.45 kWh/m² to a high of 5.9 kWh/m² in June across the year — September's 2.86 kWh/m² falls in the middle.

01234151015202530
Solar energy (kWh/m²)Level
13.6Moderate
23.5Moderate
33.5Moderate
43.4Moderate
53.4Moderate
63.3Moderate
73.3Moderate
83.2Moderate
93.2Moderate
103.1Moderate
113.1Moderate
123.0Moderate
133.0Moderate
142.9Moderate
152.9Moderate
162.9Moderate
172.8Moderate
182.8Moderate
192.7Moderate
202.7Moderate
212.6Moderate
222.6Moderate
232.5Moderate
242.5Moderate
252.5Moderate
262.4Moderate
272.4Moderate
282.3Moderate
292.3Moderate
302.2Moderate
Planning a trip in September

Is September a good time to visit Ust’-Kut?

Our two travel scores rate September for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

2.9
Sightseeing
5th-best month of the year
0.1
Beach & pool
5th-best month of the year

September is a weaker month for outdoor sightseeing in Ust’-Kut.

What to pack for Ust’-Kut in September

From September's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In September, Ust’-Kut sees daytime highs around 12°C and nights near 2°C. Pack a warm layer. Worth having: rain gear. About 11 days see rain.

a warm layerrain gear

UV index in Ust’-Kut in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 3. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Ust’-Kut peaks around June 21 at about 5 (high) — a little sun protection helps at midday. It bottoms out near December 19 at about 0 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 5 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighModerateLowJun 21UV 5Dec 19UV 0
UV index (midday)Level
Jan0Low
Feb1Low
Mar2Low
Apr4Moderate
May5Moderate
Jun6High
Jul5High
Aug5Moderate
Sep3Moderate
Oct1Low
Nov0Low
Dec0Low

Air quality in Ust’-Kut in September

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where September falls, not just the annual average.

Air quality in Ust’-Kut is worst in July — around 56 µg/m³ PM2.5 (unhealthy), about 46.8× the cleanest month (December, 1 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0204060JanFebMarAprMayJunJulAugSepOctNovDecGoodPoorPoorModerateGoodJul 2155 µg/m³Dec 181 µg/m³
PM2.5 (µg/m³)Level
Jan2Good
Feb5Good
Mar5Good
Apr10Good
May11Good
Jun42Poor
Jul56Unhealthy
Aug52Poor
Sep39Poor
Oct16Moderate
Nov3Good
Dec1Good
Location & terrain

Where is Ust’-Kut?

Ust’-Kut sits at 56.8°N, 105.8°E, 285 m above sea level, in Russia. The nearest listed city is Zheleznogorsk-Ilimskiy, 104 km away.

Topography around Ust’-Kut

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Ust’-Kut.

Within 3 km, the terrain around Ust’-Kut has significant variations in elevation — a maximum elevation change of 406 m around an average of 412 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 492 m; within 80 km, large variations in elevation — a maximum elevation change of 729 m.

The land around Ust’-Kut is covered by trees (72%) and artificial surfaces (21%) within 3 km, trees (93%) within 16 km, and trees (99%) within 80 km.

3 km
406 m
16 km
492 m
80 km
729 m
treesgrasslandartificial surfacesbare terrainwater
September weather nearby: Zheleznogorsk-Ilimskiy 104 km · Ust’-Ilimsk 230 km · Severobaykal’sk 254 km · Bratsk 267 km · Vikhorevka 293 km · Sayansk 375 km · Chunskiy 386 km · Zima 398 km

Russia travel facts

Travel advisory
Level 4
Do Not Travel
Power plugs
Type C / F
230 V · 50 Hz
Prices
≈ 32% of US
price level, 2025
GDP per capita
$17,547
2025
Happiness
5.8 / 10
World Happiness, 2025
Safe drinking water
76%
of population, 2024
Homicide rate
6.8
per 100k, 2021
Road deaths
12
per 100k/yr, 2019
Income group
High
World Bank
English
Moderate
EF EPI 521
Religion
other Christian 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Ust’-Kut (56.7979°, 105.7866°, elevation 285 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).