Ust’-Ilimsk weather in September

In September, Ust’-Ilimsk sees average daytime highs of 12°C and overnight lows near 4°C, with 52 mm of precipitation across 11 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 14% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 h 48 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’-Ilimsk's 4th-clearest and 8th-windiest month. For the whole year in context, see Ust’-Ilimsk's year-round climate.

Daytime high
12°
5th warmest
Overnight low
9th coldest
Precipitation
52 mm
11 wet days
Daylight
12 h 30 min
6:49 AM – 7:19 PM
Cloud cover
72%
4th clearest
Wind
11 km/h
8th windiest
Solar energy
2.75 kWh/m²
Travel score
2.9
out of 10

Ust’-Ilimsk is city in Russia.

Density
438/km²
people per km²
Founded
1966

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’-Ilimsk reaches about 12°C in the afternoon and slips back to 4°C overnight — a 8°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°20°151015202530
Avg high (°C)Avg low (°C)
1167
2167
3167
4157
5156
6156
7146
8145
9145
10145
11135
12134
13134
14124
15124
16123
17123
18113
19113
20112
21102
22102
23102
2491
2591
2691
2781
2880
2980
3070

How September really feels in Ust’-Ilimsk

Once humidity and wind are folded in, September averages 0 days that feel above 32°C and 13 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
13
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’-Ilimsk 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-19° / -26°155.19.16.90.0
Feb-14° / -23°124.57.98.90.0
Mar-4° / -14°196.38.711.40.0
Apr / -6°287.86.1140.3
May13° / 4310.61.616.33.5
Jun21° / 10°5610.6017.76.3
Jul24° / 13°6010017.26.8
Aug20° / 11°579.9015.16.2
Sep12° / 52110.912.52.9
Oct / -5°4111.49.19.90.1
Nov-10° / -17°319.712.67.60.0
Dec-18° / -25°227.710.76.30.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 14% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 12% of September, with mostly cloudy or overcast conditions the remaining 74%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
12872
22872
32773
42773
52674
62674
72674
82674
92674
102773
112773
122773
132773
142773
152674
162674
172674
182674
192773
202674
212674
222674
232674
242674
252674
262575
272476
282476
292278
302179

Chance of precipitation in September

Any precipitationSnow

Ust’-Ilimsk gets around 52 mm of rain and snow over 11 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 36% and peaks near 38% on the wettest days, and about 1 day brings snow.

0%10%20%30%40%50%151015202530
Rain chance (%)Snow chance (%)
1370
2380
3380
4381
5381
6381
7381
8381
9381
10382
11382
12372
13372
14362
15362
16363
17353
18353
19353
20354
21354
22355
23355
24356
25357
26358
27359
283610
293611
303712

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 99% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)
1964
2973
3982
4982
5982
6991
7991
8991
9991
10991
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 11 km/h in September.

Across September, daily wind ranges from about 11 km/h on the calmest days to 12 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
111calm
211calm
311calm
411calm
511calm
611calm
711calm
811calm
911calm
1011calm
1111calm
1211calm
1311calm
1411calm
1511calm
1611calm
1711calm
1811calm
1911calm
2011calm
2111calm
2211calm
2311calm
2411calm
2511calm
2611calm
2711calm
2811calm
2912calm
3012calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 h 48 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 150 minutes over September. Sunrise moves from 6:16 AM to 7:20 AM, and sunset from 8:02 PM to 6:37 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.86:168:02
213.76:187:59
313.66:207:57
413.56:227:54
513.46:257:51
613.46:277:48
713.36:297:45
813.26:317:42
913.16:337:39
1013.06:367:36
1112.96:387:33
1212.86:407:30
1312.86:427:27
1412.76:447:24
1512.66:477:21
1612.56:497:19
1712.46:517:16
1812.36:537:13
1912.26:557:10
2012.26:587:07
2112.17:007:04
2212.07:027:01
2311.97:046:58
2411.87:076:55
2511.77:096:52
2611.67:116:49
2711.57:136:46
2811.57:156:43
2911.47:186:40
3011.37:206:37

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 2.75 kWh/m².

For context, solar energy here swings from a low near 0.36 kWh/m² to a high of 5.98 kWh/m² in June across the year — September's 2.75 kWh/m² falls in the middle.

01234151015202530
Solar energy (kWh/m²)Level
13.5Moderate
23.4Moderate
33.4Moderate
43.3Moderate
53.3Moderate
63.2Moderate
73.2Moderate
83.1Moderate
93.1Moderate
103.0Moderate
113.0Moderate
122.9Moderate
132.9Moderate
142.8Moderate
152.8Moderate
162.7Moderate
172.7Moderate
182.6Moderate
192.6Moderate
202.5Moderate
212.5Moderate
222.4Moderate
232.4Moderate
242.3Moderate
252.3Moderate
262.2Moderate
272.2Moderate
282.1Moderate
292.1Moderate
302.0Moderate
Planning a trip in September

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

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’-Ilimsk.

What to pack for Ust’-Ilimsk in September

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

In September, Ust’-Ilimsk sees daytime highs around 12°C and nights near 4°C. Pack a warm layer. Worth having: rain gear. About 11 days see rain.

a warm layerrain gear

UV index in Ust’-Ilimsk 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’-Ilimsk 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
Apr3Moderate
May4Moderate
Jun5High
Jul5High
Aug5Moderate
Sep3Moderate
Oct1Low
Nov0Low
Dec0Low

Air quality in Ust’-Ilimsk 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’-Ilimsk is worst in July — around 35 µg/m³ PM2.5 (moderate), about 26.7× the cleanest month (December, 1 µg/m³).

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

010203040JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1934 µg/m³Dec 212 µg/m³
PM2.5 (µg/m³)Level
Jan3Good
Feb4Good
Mar5Good
Apr9Good
May10Good
Jun27Moderate
Jul35Moderate
Aug30Moderate
Sep19Moderate
Oct29Moderate
Nov7Good
Dec1Good
Location & terrain

Where is Ust’-Ilimsk?

Ust’-Ilimsk sits at 58.0°N, 102.7°E, 278 m above sea level, in Russia. The nearest listed city is Zheleznogorsk-Ilimskiy, 181 km away.

Topography around Ust’-Ilimsk

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

Within 3 km, the terrain around Ust’-Ilimsk has only modest variations in elevation — a maximum elevation change of 235 m around an average of 276 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 348 m; within 80 km, large variations in elevation — a maximum elevation change of 627 m.

The land around Ust’-Ilimsk is covered by trees (65%) and water (21%) within 3 km, trees (83%) within 16 km, and trees (93%) within 80 km.

3 km
235 m
16 km
348 m
80 km
627 m
treesgrasslandartificial surfacesbare terrainwater
September weather nearby: Zheleznogorsk-Ilimskiy 181 km · Kodinsk 215 km · Bratsk 217 km · Vikhorevka 227 km · Ust’-Kut 230 km · Chunskiy 280 km · Tayshet 365 km · Tulun 403 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’-Ilimsk (58.0006°, 102.6619°, elevation 278 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).