Bielsko-Biala weather in September

In September, Bielsko-Biala sees average daytime highs of 18°C and overnight lows near 9°C, with 100 mm of rain across 13 wet days and about 12.4 hours of daylight. It is the 4th-warmest and 5th-wettest month of the year here.

Highs ease over the month, from about 20°C in the first days to 16°C by the end. The sky is clear or mostly clear about 25% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 h 18 min at the start of September to 11 h 30 min by month's end. Set against the rest of the year, September is Bielsko-Biala's 3rd-clearest and 8th-windiest month. For the whole year in context, see Bielsko-Biala's year-round climate.

Daytime high
18°
4th warmest
Overnight low
9th coldest
Rainfall
100 mm
13 wet days
Daylight
12 h 24 min
5:27 AM – 5:49 PM
Cloud cover
63%
3rd clearest
Wind
10 km/h
8th windiest
Solar energy
3.1 kWh/m²
Travel score
5.2
out of 10

Bielsko-Biala is city in Silesian Voivodeship, Poland.

Air quality
Elevated
PM2.5 21.6 µg/m³ · 2019
Density
1,412/km²
people per km²
Founded
1312

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 20°C in the first days to 16°C by the end.

A typical September day in Bielsko-Biala reaches about 18°C in the afternoon and slips back to 9°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 12°C and 23°C. Set against its neighbours, September runs about 5°C cooler than August and about 5°C warmer than October.

10°20°30°151015202530
Avg high (°C)Avg low (°C)
12011
22011
32011
42010
51910
61910
71910
81910
91910
101910
11199
12189
13189
14189
15189
16189
17189
18178
19178
20178
21178
22178
23178
24168
25168
26168
27167
28167
29167
30167

How September really feels in Bielsko-Biala

Once humidity and wind are folded in, September averages 0 days that feel above 32°C and 0 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
0
wind chill below the day's low

September sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Bielsko-Biala weather by month

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

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -5°6613.110.78.40.0
Feb / -4°6312.39.99.70.0
Mar / -1°7213.6711.50.8
Apr13° / 73132.813.53.3
May18° / 12016.90.215.14.8
Jun21° / 11°12316.10165.4
Jul23° / 13°14117.3015.75.7
Aug23° / 13°10613.3014.26.3
Sep18° / 10013012.45.2
Oct13° / 7611.91.410.53.3
Nov / 6711.95.38.80.8
Dec / -3°6412.29.180.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 25% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 17% of September, with mostly cloudy or overcast conditions the remaining 59%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14654
24555
34555
44456
54456
64456
74357
84357
94357
104357
114258
124258
134258
144060
154060
164060
174060
184060
194060
203961
213961
224060
234060
244060
254060
264060
274060
284060
294060
304060

Chance of precipitation in September

Any precipitation

Bielsko-Biala gets around 100 mm of rain over 13 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 43% and peaks near 47% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%151015202530
Rain chance (%)
147
247
347
447
547
647
746
846
946
1045
1144
1244
1343
1442
1542
1642
1741
1841
1941
2041
2141
2240
2340
2440
2540
2640
2740
2840
2940
3040

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 83% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
167276
269265
370264
471254
573243
674233
775232
876222
978211
1078211
1179201
1280191
1382180
1483170
1584160
1685150
1786140
1887130
1988120
2089110
2189110
2290100
239190
249280
259370
269370
279460
289460
299550
309550

Wind in September

Winds average 10 km/h in September.

Across September, daily wind ranges from about 9 km/h on the calmest days to 10 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
19calm
29calm
39calm
49calm
510calm
610calm
710calm
810calm
910calm
1010calm
1110calm
1210calm
1310calm
1410calm
1510calm
1610calm
1710calm
1810calm
1910calm
2010calm
2110calm
2210calm
2310calm
2410calm
2510calm
2610calm
2710calm
2810calm
2910calm
3010calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 h 18 min at the start of September to 11 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 108 minutes over September. Sunrise moves from 5:04 AM to 5:49 AM, and sunset from 6:23 PM to 5:17 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.35:046:23
213.25:066:21
313.25:076:18
413.15:096:16
513.15:106:14
613.05:126:12
712.95:136:10
812.95:156:07
912.85:166:05
1012.75:186:03
1112.75:196:00
1212.65:215:58
1312.65:235:56
1412.55:245:54
1512.45:265:51
1612.45:275:49
1712.35:295:47
1812.25:305:45
1912.25:325:42
2012.15:335:40
2112.05:355:38
2212.05:365:35
2311.95:385:33
2411.95:395:31
2511.85:415:29
2611.75:435:26
2711.75:445:24
2811.65:465:22
2911.55:475:20
3011.55:495:17

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.1 kWh/m².

For context, solar energy here swings from a low near 0.77 kWh/m² to a high of 5.2 kWh/m² in June across the year — September's 3.1 kWh/m² falls in the middle.

01234151015202530
Solar energy (kWh/m²)Level
13.7Moderate
23.7Moderate
33.6Moderate
43.6Moderate
53.5Moderate
63.5Moderate
73.5Moderate
83.4Moderate
93.4Moderate
103.4Moderate
113.3Moderate
123.3Moderate
133.2Moderate
143.2Moderate
153.1Moderate
163.1Moderate
173.1Moderate
183.0Moderate
193.0Moderate
202.9Moderate
212.9Moderate
222.9Moderate
232.8Moderate
242.8Moderate
252.7Moderate
262.7Moderate
272.6Moderate
282.6Moderate
292.5Moderate
302.5Moderate
Planning a trip in September

Is September a good time to visit Bielsko-Biala?

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

5.2
Sightseeing
4th-best month of the year
1.7
Beach & pool
4th-best month of the year

September is a reasonable time to visit Bielsko-Biala for sightseeing.

What to pack for Bielsko-Biala in September

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

In September, Bielsko-Biala sees daytime highs around 18°C and nights near 9°C. Worth packing: rain gear. About 13 days see rain.

rain gear

UV index in Bielsko-Biala in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 4 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Bielsko-Biala peaks around June 22 at about 7 (high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near December 19 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 7 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighModerateLowJun 22UV 7Dec 19UV 1
UV index (midday)Level
Jan1Low
Feb1Low
Mar4Moderate
Apr5Moderate
May6High
Jun7High
Jul7High
Aug6High
Sep4Moderate
Oct2Moderate
Nov1Low
Dec1Low

Air quality in Bielsko-Biala 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 Bielsko-Biala is worst in June — around 26 µg/m³ PM2.5 (moderate), about 1.7× the cleanest month (December, 15 µg/m³).

Seasonal pattern from CAMS reanalysis, scaled to Bielsko-Biala's WHO annual average of 21.6 µg/m³.

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateJun 1726 µg/m³Dec 1316 µg/m³
PM2.5 (µg/m³)Level
Jan19Moderate
Feb20Moderate
Mar24Moderate
Apr25Moderate
May25Moderate
Jun26Moderate
Jul25Moderate
Aug25Moderate
Sep21Moderate
Oct18Moderate
Nov17Moderate
Dec15Moderate
Location & terrain

Where is Bielsko-Biala?

Bielsko-Biala sits at 49.8°N, 19.0°E, 330 m above sea level, in Poland. The nearest listed city is Czechowice-Dziedzice, 11 km away.

Topography around Bielsko-Biala

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Bielsko-Biala.

Within 3 km, the terrain around Bielsko-Biala has only modest variations in elevation — a maximum elevation change of 131 m around an average of 344 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 1,021 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,717 m.

The land around Bielsko-Biala is covered by trees (46%) and artificial surfaces (43%) within 3 km, trees (55%) within 16 km, and trees (59%) within 80 km.

3 km
131 m
16 km
1,021 m
80 km
1,717 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Czechowice-Dziedzice 11 km · Kęty 14 km · Żywiec 18 km · Pszczyna 19 km · Ustroń 21 km · Andrychów 21 km · Auschwitz 26 km · Bieruń 30 km

Poland travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type C / E
230 V · 50 Hz
Prices
≈ 52% of US
price level, 2025
GDP per capita
$28,420
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
89%
of population, 2024
Homicide rate
0.8
per 100k, 2023
Road deaths
9.4
per 100k/yr, 2019
Income group
High
World Bank
English
Very high
EF EPI 600
Religion
Roman Catholic 71%refused to answer 21%no religion 7%

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 Bielsko-Biala (49.8225°, 19.0469°, elevation 330 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).