Mladá Boleslav weather in September

In September, Mladá Boleslav sees average daytime highs of 19°C and overnight lows near 10°C, with 58 mm of rain across 9 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 21°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 Mladá Boleslav's 4th-clearest and 9th-windiest month. For the whole year in context, see Mladá Boleslav's year-round climate.

Daytime high
19°
4th warmest
Overnight low
10°
9th coldest
Rainfall
58 mm
9 wet days
Daylight
12 h 24 min
5:43 AM – 6:06 PM
Cloud cover
62%
4th clearest
Wind
10 km/h
9th windiest
Solar energy
3.15 kWh/m²
Travel score
6.0
out of 10

Mladá Boleslav is town in Central Bohemian Region, Czech Republic.

Air quality
Elevated
PM2.5 15.6 µg/m³ · 2019
Density
1,511/km²
people per km²
Founded
1130

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 21°C in the first days to 16°C by the end.

A typical September day in Mladá Boleslav reaches about 19°C in the afternoon and slips back to 10°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 13°C and 24°C. Set against its neighbours, September runs about 5°C cooler than August and about 6°C warmer than October.

10°20°30°151015202530
Avg high (°C)Avg low (°C)
12112
22112
32112
42111
52011
62011
72011
82011
92011
102011
111910
121910
131910
141910
151910
161910
171810
18189
19189
20189
21189
22179
23179
24179
25179
26178
27178
28168
29168
30168

How September really feels in Mladá Boleslav

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.

Mladá Boleslav 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 / -3°5211.56.98.30.0
Feb / -2°429.45.49.70.0
Mar / 5211.13.611.51.2
Apr14° / 3890.813.53.9
May18° / 5811.60.115.25.7
Jun22° / 12°6711.5016.16.2
Jul24° / 14°7812.6015.86.5
Aug24° / 14°6610.4014.36.8
Sep19° / 10°589012.46.0
Oct13° / 509.80.210.53.3
Nov / 489.92.48.80.7
Dec / -2°5211.15.67.90.0

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 16% of September, with mostly cloudy or overcast conditions the remaining 60%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14258
24357
34258
44258
54258
64159
74159
84258
94258
104258
114258
124258
134357
144357
154357
164258
174159
184159
194159
204060
214060
224060
233961
243961
253961
263862
273763
283763
293664
303466

Chance of precipitation in September

Any precipitation

Mladá Boleslav gets around 58 mm of rain over 9 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 30% and peaks near 34% on the wettest days.

0%10%20%30%40%151015202530
Rain chance (%)
133
233
333
433
532
632
732
832
931
1030
1130
1229
1329
1428
1528
1628
1728
1828
1928
2028
2128
2229
2329
2429
2530
2631
2732
2833
2933
3034

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 88% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
174224
275214
376213
477203
579192
680182
781172
882162
982162
1083152
1185141
1286131
1387121
1487121
1588111
1689101
179091
189181
199181
209370
219460
229460
239550
249550
259550
269640
279640
289640
299640
309730

Wind in September

Winds average 10 km/h in September.

Across September, daily wind ranges from about 10 km/h on the calmest days to 11 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
110calm
210calm
310calm
410calm
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
3011calm

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 5:20 AM to 6:06 AM, and sunset from 6:40 PM to 5:34 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.35:206:40
213.35:226:38
313.25:236:36
413.15:256:33
513.15:266:31
613.05:286:29
713.05:296:27
812.95:316:24
912.85:326:22
1012.85:346:20
1112.75:366:17
1212.65:376:15
1312.65:396:13
1412.55:406:11
1512.45:426:08
1612.45:436:06
1712.35:456:04
1812.25:476:01
1912.25:485:59
2012.15:505:57
2112.05:515:54
2212.05:535:52
2311.95:555:50
2411.95:565:47
2511.85:585:45
2611.75:595:43
2711.76:015:40
2811.66:035:38
2911.56:045:36
3011.56:065:34

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.15 kWh/m².

For context, solar energy here swings from a low near 0.7 kWh/m² to a high of 5.41 kWh/m² in June across the year — September's 3.15 kWh/m² falls in the middle.

01234151015202530
Solar energy (kWh/m²)Level
13.8Moderate
23.8Moderate
33.7Moderate
43.7Moderate
53.6Moderate
63.6Moderate
73.5Moderate
83.5Moderate
93.4Moderate
103.4Moderate
113.4Moderate
123.3Moderate
133.3Moderate
143.2Moderate
153.2Moderate
163.1Moderate
173.1Moderate
183.1Moderate
193.0Moderate
203.0Moderate
212.9Moderate
222.9Moderate
232.9Moderate
242.8Moderate
252.8Moderate
262.7Moderate
272.7Moderate
282.6Moderate
292.6Moderate
302.5Moderate
Planning a trip in September

Is September a good time to visit Mladá Boleslav?

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

6.0
Sightseeing
4th-best month of the year
2.4
Beach & pool
4th-best month of the year

September is a reasonable time to visit Mladá Boleslav for sightseeing.

What to pack for Mladá Boleslav in September

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

In September, Mladá Boleslav sees daytime highs around 19°C and nights near 10°C. Worth packing: rain gear. About 9 days see rain.

rain gear

UV index in Mladá Boleslav in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 5 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Mladá Boleslav peaks around June 21 at about 7 (high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near December 22 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 21UV 7Dec 22UV 1
UV index (midday)Level
Jan1Low
Feb2Low
Mar4Moderate
Apr4Moderate
May6High
Jun7High
Jul7High
Aug6High
Sep5Moderate
Oct2Moderate
Nov1Low
Dec1Low

Air quality in Mladá Boleslav 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 Mladá Boleslav is worst in March — around 19 µg/m³ PM2.5 (moderate), and holds fairly steady the rest of the year.

Seasonal pattern from CAMS reanalysis, scaled to Mladá Boleslav's WHO annual average of 15.6 µg/m³.

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateMar 2319 µg/m³Dec 1112 µg/m³
PM2.5 (µg/m³)Level
Jan14Moderate
Feb15Moderate
Mar19Moderate
Apr18Moderate
May17Moderate
Jun18Moderate
Jul16Moderate
Aug17Moderate
Sep15Moderate
Oct13Moderate
Nov12Moderate
Dec12Moderate
Location & terrain

Where is Mladá Boleslav?

Mladá Boleslav sits at 50.4°N, 14.9°E, 241 m above sea level, in Czechia. The nearest listed city is Brandýs nad Labem-Stará Boleslav, 30 km away.

Brandýs nad Labem-Stará BoleslavMělníkJičínNeratovicePoděbradyJablonec nad NisouČeská LípaLiberec

Topography around Mladá Boleslav

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Mladá Boleslav.

Within 3 km, the terrain around Mladá Boleslav has only modest variations in elevation — a maximum elevation change of 171 m around an average of 238 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 222 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,573 m.

The land around Mladá Boleslav is covered by artificial surfaces (31%), cropland (29%) and trees (25%) within 3 km, cropland (53%) and trees (32%) within 16 km, and trees (42%) and cropland (37%) within 80 km.

3 km
171 m
16 km
222 m
80 km
1,573 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Brandýs nad Labem-Stará Boleslav 30 km · Mělník 31 km · Jičín 32 km · Neratovice 32 km · Poděbrady 34 km · Jablonec nad Nisou 40 km · Česká Lípa 40 km · Liberec 41 km

Czechia travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type C / E
230 V · 50 Hz
Prices
≈ 59% of US
price level, 2025
GDP per capita
$35,917
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
0.8
per 100k, 2023
Road deaths
5.9
per 100k/yr, 2019
Income group
High
World Bank
English
High
EF EPI 582
Religion
none 48%believers unaffiliated with a religious society 9%Roman Catholic 7%other believers belonging to a church or religious society 6%

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 Mladá Boleslav (50.4113°, 14.9032°, elevation 241 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).