Ostrov weather in September

In September, Ostrov sees average daytime highs of 17°C and overnight lows near 8°C, with 60 mm of rain across 10.4 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 18°C in the first days to 14°C by the end. The sky is clear or mostly clear about 21% 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 Ostrov's 3rd-clearest and 9th-windiest month. For the whole year in context, see Ostrov's year-round climate.

Daytime high
17°
4th warmest
Overnight low
9th coldest
Rainfall
60 mm
10.4 wet days
Daylight
12 h 24 min
5:51 AM – 6:14 PM
Cloud cover
65%
3rd clearest
Wind
10 km/h
9th windiest
Solar energy
3.15 kWh/m²
Travel score
5.0
out of 10

Ostrov is town in the Czech Republic.

Density
311/km²
people per km²
Founded
1331

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 18°C in the first days to 14°C by the end.

A typical September day in Ostrov reaches about 17°C in the afternoon and slips back to 8°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 11°C and 22°C. Set against its neighbours, September runs about 5°C cooler than August and about 6°C warmer than October.

10°15°20°25°151015202530
Avg high (°C)Avg low (°C)
11910
21910
31910
4189
5189
6189
7189
8189
9189
10179
11179
12178
13178
14178
15178
16168
17168
18167
19167
20167
21167
22157
23157
24157
25157
26157
27157
28146
29146
30146

How September really feels in Ostrov

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.

Ostrov 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 / -4°5011.58.78.30.0
Feb / -4°398.96.79.70.0
Mar / -1°5211.96.111.50.5
Apr11° / 4711.41.813.52.8
May16° / 70140.115.24.6
Jun19° / 10°8213.9016.15.5
Jul22° / 12°9014015.75.9
Aug21° / 12°7812.8014.36.1
Sep17° / 6010.4012.45.0
Oct11° / 5210.50.810.52.5
Nov / 499.548.80.3
Dec / -3°5210.68.17.90.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 21% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 14% of September, with mostly cloudy or overcast conditions the remaining 65%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
13862
23862
33862
43862
53763
63862
73862
83763
93862
103763
113862
123763
133763
143664
153763
163565
173565
183565
193565
203466
213367
223367
233268
243268
253169
263169
272971
282971
292971
302872

Chance of precipitation in September

Any precipitation

Ostrov gets around 60 mm of rain over 10.4 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 36% and peaks near 40% on the wettest days.

0%10%20%30%40%50%151015202530
Rain chance (%)
140
240
339
439
539
639
739
839
938
1038
1138
1237
1336
1436
1535
1634
1734
1834
1933
2033
2132
2232
2332
2432
2532
2633
2733
2834
2935
3035

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 93% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
181181
282171
383161
484151
586140
687130
788120
888120
989110
1090100
1190100
129190
139280
149370
159370
169460
179550
189640
199640
209730
219730
229820
239820
249820
259910
269910
279910
289910
299910
309910

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 5:28 AM to 6:14 AM, and sunset from 6:48 PM to 5:42 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.35:286:48
213.35:306:46
313.25:316:43
413.15:336:41
513.15:346:39
613.05:366:37
713.05:376:34
812.95:396:32
912.85:406:30
1012.85:426:28
1112.75:446:25
1212.65:456:23
1312.65:476:21
1412.55:486:18
1512.45:506:16
1612.45:516:14
1712.35:536:11
1812.25:556:09
1912.25:566:07
2012.15:586:04
2112.05:596:02
2212.06:016:00
2311.96:025:58
2411.96:045:55
2511.86:065:53
2611.76:075:51
2711.76:095:48
2811.66:105:46
2911.56:125:44
3011.56:145:42

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 0.73 kWh/m² to a high of 5.4 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
183.0Moderate
193.0Moderate
203.0Moderate
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 Ostrov?

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

5.0
Sightseeing
4th-best month of the year
1.0
Beach & pool
4th-best month of the year

September is a reasonable time to visit Ostrov for sightseeing.

What to pack for Ostrov in September

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

In September, Ostrov sees daytime highs around 17°C and nights near 8°C. Worth packing: a warm layer and rain gear. About 10 days see rain.

a warm layerrain gear

UV index in Ostrov 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 Ostrov peaks around June 22 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 22UV 7Jan 1UV 1
UV index (midday)Level
Jan1Low
Feb2Low
Mar4Moderate
Apr4Moderate
May6High
Jun7Very high
Jul7Very high
Aug7High
Sep4Moderate
Oct3Moderate
Nov1Low
Dec1Low

Air quality in Ostrov 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 Ostrov is worst in April — around 18 µg/m³ PM2.5 (moderate), about 1.7× the cleanest month (December, 11 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodApr 1518 µg/m³Dec 1311 µg/m³
PM2.5 (µg/m³)Level
Jan13Moderate
Feb14Moderate
Mar17Moderate
Apr18Moderate
May16Moderate
Jun18Moderate
Jul16Moderate
Aug16Moderate
Sep16Moderate
Oct13Moderate
Nov12Good
Dec11Good
Location & terrain

Where is Ostrov?

Ostrov sits at 50.3°N, 12.9°E, 398 m above sea level, in Czechia. The nearest listed city is Karlovy Vary, 9.0 km away.

SchwarzenbergAnnaberg-BuchholzAueChomutovSchneeberg

Topography around Ostrov

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

Within 3 km, the terrain around Ostrov has only modest variations in elevation — a maximum elevation change of 239 m around an average of 441 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 947 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,205 m.

The land around Ostrov is covered by trees (41%), grassland (26%) and cropland (22%) within 3 km, trees (71%) and grassland (22%) within 16 km, and trees (48%) and cropland (30%) within 80 km.

3 km
239 m
16 km
947 m
80 km
1,205 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Karlovy Vary 9.0 km · Kadaň 25 km · Sokolov 25 km · Schwarzenberg 28 km · Annaberg-Buchholz 31 km · Aue 36 km · Chomutov 38 km · Schneeberg 38 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 Ostrov (50.3059°, 12.9391°, elevation 398 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).