Kościerzyna weather in September

In September, Kościerzyna sees average daytime highs of 17°C and overnight lows near 9°C, with 53 mm of rain across 9.2 wet days and about 12.5 hours of daylight. It is the 4th-warmest and 5th-wettest month of the year here.

Highs ease over the month, from about 19°C in the first days to 15°C by the end. The sky is clear or mostly clear about 20% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 h 30 min at the start of September to 11 h 24 min by month's end. Set against the rest of the year, September is Kościerzyna's 6th-clearest and 8th-windiest month. For the whole year in context, see Kościerzyna's year-round climate.

Daytime high
17°
4th warmest
Overnight low
9th coldest
Rainfall
53 mm
9.2 wet days
Daylight
12 h 24 min
5:30 AM – 5:55 PM
Cloud cover
66%
6th clearest
Wind
14 km/h
8th windiest
Solar energy
2.81 kWh/m²
Travel score
5.3
out of 10

Kościerzyna is city and urban gmina of Poland.

Air quality
Elevated
PM2.5 22.8 µg/m³ · 2018
Density
1,474/km²
people per km²
Founded
1250

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 19°C in the first days to 15°C by the end.

A typical September day in Kościerzyna reaches about 17°C in the afternoon and slips back to 9°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 13°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)
11911
21911
31911
41911
51911
61810
71810
81810
91810
101810
111810
121810
13179
14179
15179
16179
17179
18179
19179
20169
21168
22168
23168
24168
25168
26158
27158
28158
29157
30157

How September really feels in Kościerzyna

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.

Kościerzyna 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°4310.15.87.70.0
Feb / -3°348.75.29.40.0
Mar / -1°42103.711.50.4
Apr12° / 379.41.113.73.0
May17° / 6311.9015.75.1
Jun19° / 11°7012.6016.85.7
Jul22° / 13°8813.2016.46.1
Aug22° / 13°7012.5014.66.2
Sep17° / 539.2012.55.3
Oct11° / 4610.10.210.22.8
Nov / 378.92.18.30.4
Dec / -2°4510.357.20.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 20% 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 64%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
13961
23862
33862
43763
53664
63664
73565
83565
93466
103565
113565
123466
133466
143466
153466
163565
173565
183565
193664
203664
213664
223664
233664
243763
253763
263763
273763
283664
293565
303565

Chance of precipitation in September

Any precipitation

Kościerzyna gets around 53 mm of rain over 9.2 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 32% and peaks near 42% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%40%50%151015202530
Rain chance (%)
142
241
341
441
540
639
738
837
936
1035
1134
1233
1331
1430
1529
1628
1727
1826
1925
2025
2125
2225
2325
2426
2526
2627
2728
2828
2929
3030

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 87% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
172244
273234
374224
476213
576213
677203
778193
880182
981172
1082162
1183152
1284142
1385132
1487121
1588111
1689101
179091
189181
199181
209370
219460
229460
239460
249550
259550
269550
279550
289550
299550
309550

Wind in September

Winds average 14 km/h in September.

Across September, daily wind ranges from about 14 km/h on the calmest days to 15 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
114light breeze
214light breeze
314light breeze
414light breeze
514light breeze
614light breeze
714light breeze
814light breeze
914light breeze
1014light breeze
1114light breeze
1214light breeze
1314light breeze
1414light breeze
1514light breeze
1614light breeze
1714light breeze
1814light breeze
1914light breeze
2014light breeze
2114light breeze
2214light breeze
2314light breeze
2415light breeze
2515light breeze
2615light breeze
2715light breeze
2815light breeze
2915light breeze
3015light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 h 30 min at the start of September to 11 h 24 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 126 minutes over September. Sunrise moves from 5:02 AM to 5:56 AM, and sunset from 6:34 PM to 5:19 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.55:026:34
213.55:046:31
313.45:066:29
413.35:076:26
513.25:096:24
613.25:116:21
713.15:136:18
813.05:156:16
912.95:176:13
1012.95:186:11
1112.85:206:08
1212.75:226:06
1312.65:246:03
1412.65:266:00
1512.55:285:58
1612.45:305:55
1712.45:315:53
1812.35:335:50
1912.25:355:47
2012.15:375:45
2112.15:395:42
2212.05:415:40
2311.95:435:37
2411.85:445:34
2511.85:465:32
2611.75:485:29
2711.65:505:27
2811.55:525:24
2911.55:545:22
3011.45:565:19

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 2.81 kWh/m².

For context, solar energy here swings from a low near 0.43 kWh/m² to a high of 5.31 kWh/m² in June across the year — September's 2.81 kWh/m² falls in the middle.

01234151015202530
Solar energy (kWh/m²)Level
13.5Moderate
23.4Moderate
33.4Moderate
43.3Moderate
53.2Moderate
63.2Moderate
73.1Moderate
83.1Moderate
93.0Moderate
103.0Moderate
113.0Moderate
122.9Moderate
132.9Moderate
142.9Moderate
152.8Moderate
162.8Moderate
172.8Moderate
182.7Moderate
192.7Moderate
202.6Moderate
212.6Moderate
222.6Moderate
232.5Moderate
242.5Moderate
252.5Moderate
262.4Moderate
272.4Moderate
282.3Moderate
292.3Moderate
302.2Moderate
Planning a trip in September

Is September a good time to visit Kościerzyna?

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

5.3
Sightseeing
4th-best month of the year
1.3
Beach & pool
4th-best month of the year

September is a reasonable time to visit Kościerzyna for sightseeing.

What to pack for Kościerzyna in September

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

In September, Kościerzyna sees daytime highs around 17°C and nights near 9°C. Worth packing: rain gear. About 9 days see rain.

rain gear

Sea temperature near Kościerzyna in September

The nearest coast averages about 17°C in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 65 km away) is warmest in August at about 19°C and coldest in February near 3°C.

The water stays below 20°C all year — cool enough that most swimmers want a wetsuit.

0°10°20°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshing
Sea temperature (°C)Comfort
Jan4Bracing
Feb3Bracing
Mar3Bracing
Apr5Bracing
May10Bracing
Jun14Bracing
Jul18Cool
Aug19Cool
Sep17Cool
Oct13Bracing
Nov9Bracing
Dec6Bracing

UV index in Kościerzyna 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 Kościerzyna peaks around June 18 at about 6 (high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near December 20 at about 0 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 6 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighModerateLowJun 18UV 6Dec 20UV 0
UV index (midday)Level
Jan1Low
Feb1Low
Mar3Moderate
Apr4Moderate
May5High
Jun6High
Jul6High
Aug5High
Sep4Moderate
Oct2Low
Nov1Low
Dec0Low

Air quality in Kościerzyna 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 Kościerzyna is worst in April — around 29 µg/m³ PM2.5 (moderate), about 2.1× the cleanest month (December, 14 µg/m³).

Seasonal pattern from CAMS reanalysis, scaled to Kościerzyna's WHO annual average of 22.8 µg/m³.

010203040JanFebMarAprMayJunJulAugSepOctNovDecModerateApr 1229 µg/m³Dec 1515 µg/m³
PM2.5 (µg/m³)Level
Jan18Moderate
Feb21Moderate
Mar28Moderate
Apr29Moderate
May26Moderate
Jun28Moderate
Jul26Moderate
Aug25Moderate
Sep22Moderate
Oct19Moderate
Nov16Moderate
Dec14Moderate
Location & terrain

Where is Kościerzyna?

Kościerzyna sits at 54.1°N, 18.0°E, 162 m above sea level, in Poland. The nearest listed city is Kartuzy, 27 km away.

Starogard GdańskiPruszcz GdańskiUjeścisko-ŁostowiceOsowaPiecki-MigowoOrunia Górna-Gdańsk Południe

Topography around Kościerzyna

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

Within 3 km, the terrain around Kościerzyna has only modest variations in elevation — a maximum elevation change of 74 m around an average of 177 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 215 m; within 80 km, significant variations in elevation — a maximum elevation change of 339 m.

The land around Kościerzyna is covered by trees (45%) and grassland (24%) within 3 km, trees (53%) and cropland (23%) within 16 km, and trees (45%) and cropland (32%) within 80 km.

3 km
74 m
16 km
215 m
80 km
339 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Kartuzy 27 km · Bytów 32 km · Starogard Gdański 40 km · Pruszcz Gdański 45 km · Ujeścisko-Łostowice 46 km · Osowa 47 km · Piecki-Migowo 47 km · Orunia Górna-Gdańsk Południe 47 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 Kościerzyna (54.1223°, 17.9812°, elevation 162 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. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. 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).