Karlštejn weather in September

In September, Karlštejn sees average daytime highs of 19°C and overnight lows near 10°C, with 58 mm of rain across 9.5 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 17°C by the end. The sky is clear or mostly clear about 23% 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 Karlštejn's 5th-clearest and 9th-windiest month. For the whole year in context, see Karlštejn's year-round climate.

Daytime high
19°
4th warmest
Overnight low
10°
9th coldest
Rainfall
58 mm
9.5 wet days
Daylight
12 h 24 min
5:47 AM – 6:09 PM
Cloud cover
63%
5th clearest
Wind
10 km/h
9th windiest
Solar energy
3.21 kWh/m²
Travel score
5.9
out of 10

Karlštejn is market town in Czech Republic.

Density
58/km²
people per km²
Founded
1348

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 17°C by the end.

A typical September day in Karlštejn 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 25°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)
12212
22112
32112
42112
52111
62111
72011
82011
92011
102011
112011
122010
131910
141910
151910
161910
171910
18189
19189
20189
21189
22189
23189
24179
25179
26178
27178
28178
29168
30168

How September really feels in Karlštejn

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.

Karlštejn 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°369.75.38.40.0
Feb / -2°318.13.89.70.0
Mar / 4310.82.911.51.5
Apr14° / 40100.713.54.0
May19° / 7113.3015.15.5
Jun22° / 12°77120166.2
Jul24° / 14°8112.8015.76.5
Aug24° / 14°7811014.36.7
Sep19° / 10°589.5012.45.9
Oct13° / 459.70.110.53.6
Nov / 398.71.58.80.9
Dec / -1°379.347.90.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 23% 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 60%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14555
24456
34456
44357
54357
64357
74357
84258
94159
104258
114258
124159
134159
144060
154060
163961
173862
183862
193862
203862
213862
223763
233763
243763
253763
263763
273664
283565
293565
303565

Chance of precipitation in September

Any precipitation

Karlštejn gets around 58 mm of rain over 9.5 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 33% and peaks near 34% on the wettest days.

0%10%20%30%40%151015202530
Rain chance (%)
132
232
332
432
532
632
733
833
933
1033
1133
1233
1333
1433
1533
1633
1733
1833
1933
2032
2132
2232
2332
2432
2532
2632
2733
2833
2934
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 85% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
171227
273216
374215
476204
576204
678193
778193
879183
980182
1081172
1181172
1282162
1383152
1484151
1585141
1686131
1787121
1887121
1988111
2090100
219190
229190
239280
249370
259370
269460
279460
289550
299550
309550

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
2811calm
2911calm
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 5:24 AM to 6:08 AM, and sunset from 6:42 PM to 5:37 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.35:246:42
213.35:256:40
313.25:276:38
413.15:286:36
513.15:306:34
613.05:316:31
712.95:336:29
812.95:346:27
912.85:366:25
1012.75:376:22
1112.75:396:20
1212.65:406:18
1312.65:426:15
1412.55:436:13
1512.45:456:11
1612.45:476:09
1712.35:486:06
1812.25:506:04
1912.25:516:02
2012.15:535:59
2112.05:545:57
2212.05:565:55
2311.95:575:53
2411.95:595:50
2511.86:015:48
2611.76:025:46
2711.76:045:44
2811.66:055:41
2911.56:075:39
3011.56:085:37

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.21 kWh/m².

For context, solar energy here swings from a low near 0.75 kWh/m² to a high of 5.47 kWh/m² in June across the year — September's 3.21 kWh/m² falls in the middle.

01234151015202530
Solar energy (kWh/m²)Level
13.9Moderate
23.8Moderate
33.8Moderate
43.7Moderate
53.7Moderate
63.6Moderate
73.6Moderate
83.6Moderate
93.5Moderate
103.5Moderate
113.4Moderate
123.4Moderate
133.3Moderate
143.3Moderate
153.3Moderate
163.2Moderate
173.2Moderate
183.1Moderate
193.1Moderate
203.0Moderate
213.0Moderate
223.0Moderate
232.9Moderate
242.9Moderate
252.8Moderate
262.8Moderate
272.7Moderate
282.7Moderate
292.6Moderate
302.6Moderate
Planning a trip in September

Is September a good time to visit Karlštejn?

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

5.9
Sightseeing
4th-best month of the year
2.5
Beach & pool
4th-best month of the year

September is a reasonable time to visit Karlštejn for sightseeing.

What to pack for Karlštejn in September

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

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

rain gear

UV index in Karlštejn 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 Karlštejn peaks around June 21 at about 7 (very high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near January 1 at about 1 (low).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJun 21UV 7Jan 1UV 1
UV index (midday)Level
Jan1Low
Feb2Low
Mar4Moderate
Apr4Moderate
May6High
Jun7Very high
Jul7High
Aug6High
Sep4Moderate
Oct3Moderate
Nov1Low
Dec1Low

Air quality in Karlštejn 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 Karlštejn is worst in April — around 22 µg/m³ PM2.5 (moderate), and holds fairly steady the rest of the year.

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateApr 1022 µg/m³Dec 1515 µg/m³
PM2.5 (µg/m³)Level
Jan17Moderate
Feb18Moderate
Mar21Moderate
Apr22Moderate
May19Moderate
Jun21Moderate
Jul18Moderate
Aug19Moderate
Sep19Moderate
Oct17Moderate
Nov16Moderate
Dec15Moderate
Location & terrain

Where is Karlštejn?

Karlštejn sits at 49.9°N, 14.2°E, 0 m above sea level, in Czechia. The nearest listed city is Beroun, 9.0 km away.

Topography around Karlštejn

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

Within 3 km, the terrain around Karlštejn has only modest variations in elevation — a maximum elevation change of 237 m around an average of 323 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 474 m; within 80 km, large variations in elevation — a maximum elevation change of 829 m.

The land around Karlštejn is covered by trees (52%), cropland (22%) and grassland (20%) within 3 km, trees (48%) and cropland (28%) within 16 km, and cropland (43%) and trees (39%) within 80 km.

3 km
237 m
16 km
474 m
80 km
829 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Beroun 9.0 km · Stodůlky 16 km · Řepy 17 km · Modřany 18 km · Košíře 19 km · Hlubočepy 19 km · Braník 20 km · Smíchov 22 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 Karlštejn (49.9374°, 14.186°, elevation 0 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).