Karlskrona weather in September

In September, Karlskrona sees average daytime highs of 16°C and overnight lows near 11°C, with 53 mm of rain across 9.6 wet days and about 12.5 hours of daylight. It is the 4th-warmest and 7th-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 42 min at the start of September to 11 h 18 min by month's end. Set against the rest of the year, September is Karlskrona's 6th-clearest and 7th-windiest month. For the whole year in context, see Karlskrona's year-round climate.

Daytime high
16°
4th warmest
Overnight low
11°
9th coldest
Rainfall
53 mm
9.6 wet days
Daylight
12 h 30 min
5:38 AM – 6:06 PM
Cloud cover
64%
6th clearest
Wind
17 km/h
7th windiest
Solar energy
2.85 kWh/m²
Travel score
4.9
out of 10

Karlskrona is urban area in Karlskrona Municipality, Sweden.

Air quality
Good
PM10 17.1 µg/m³ · 2019
Founded
1680

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 Karlskrona reaches about 16°C in the afternoon and slips back to 11°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between 13°C and 19°C. Set against its neighbours, September runs about 4°C cooler than August and about 5°C warmer than October.

10°15°20°25°151015202530
Avg high (°C)Avg low (°C)
11812
21812
31812
41812
51712
61712
71712
81712
91711
101711
111711
121611
131611
141611
151611
161611
171611
181610
191510
201510
211510
221510
231510
241510
251510
26149
27149
28149
29149
30149

How September really feels in Karlskrona

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.

Karlskrona weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 7th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -1°4710.65.57.30.0
Feb / -2°409.25.89.10.0
Mar / -0°348.73.511.40.2
Apr / 327.50.913.81.9
May14° / 4490164.1
Jun17° / 11°559.7017.25.6
Jul20° / 14°6710.3016.86.3
Aug20° / 14°6411.6014.96.1
Sep16° / 11°539.6012.54.9
Oct11° / 5810.80.210.12.6
Nov / 56121.37.90.6
Dec / 5311.43.76.70.0

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 20% of September, with mostly cloudy or overcast conditions the remaining 59%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14753
24753
34753
44753
54753
64654
74654
84555
94555
104555
114555
124456
134357
144258
154159
164060
173961
183961
193961
203862
213862
223763
233763
243763
253763
263763
273565
283565
293565
303565

Chance of precipitation in September

Any precipitation

Karlskrona gets around 53 mm of rain over 9.6 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 38% on the wettest days.

0%10%20%30%40%50%151015202530
Rain chance (%)
138
237
337
436
536
635
735
834
934
1033
1133
1233
1333
1433
1532
1632
1732
1832
1931
2031
2131
2231
2331
2431
2532
2632
2732
2833
2933
3033

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 81% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
163316
264306
366295
468284
569274
671263
771263
873252
974242
1076231
1177221
1278211
1379201
1480191
1582180
1683170
1785150
1886140
1987130
2087130
2188120
2289110
2389110
2490100
2590100
269190
279190
289190
299280
309280

Wind in September

Winds average 17 km/h in September.

Across September, daily wind ranges from about 16 km/h on the calmest days to 18 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
116light breeze
216light breeze
316light breeze
416light breeze
516light breeze
616light breeze
716light breeze
816light breeze
917light breeze
1017light breeze
1117light breeze
1217light breeze
1317light breeze
1417light breeze
1517light breeze
1617light breeze
1717light breeze
1817light breeze
1917light breeze
2017light breeze
2117light breeze
2217light breeze
2317light breeze
2417light breeze
2517light breeze
2617light breeze
2717light breeze
2818light breeze
2918light breeze
3018light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 h 42 min at the start of September to 11 h 18 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 144 minutes over September. Sunrise moves from 5:08 AM to 6:07 AM, and sunset from 6:47 PM to 5:27 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.75:086:47
213.65:106:44
313.55:126:42
413.45:146:39
513.35:166:36
613.35:186:33
713.25:206:31
813.15:226:28
913.05:246:25
1012.95:266:22
1112.95:286:20
1212.85:306:17
1312.75:326:14
1412.65:346:11
1512.55:366:09
1612.55:386:06
1712.45:406:03
1812.35:426:00
1912.25:445:57
2012.15:465:55
2112.15:485:52
2212.05:505:49
2311.95:525:46
2411.85:545:44
2511.75:575:41
2611.75:595:38
2711.66:015:35
2811.56:035:33
2911.46:055:30
3011.36:075:27

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 2.85 kWh/m².

For context, solar energy here swings from a low near 0.33 kWh/m² to a high of 5.86 kWh/m² in June across the year — September's 2.85 kWh/m² falls in the middle.

01234151015202530
Solar energy (kWh/m²)Level
13.6Moderate
23.6Moderate
33.5Moderate
43.5Moderate
53.4Moderate
63.4Moderate
73.3Moderate
83.2Moderate
93.2Moderate
103.1Moderate
113.1Moderate
123.0Moderate
133.0Moderate
142.9Moderate
152.9Moderate
162.8Moderate
172.8Moderate
182.7Moderate
192.6Moderate
202.6Moderate
212.5Moderate
222.5Moderate
232.5Moderate
242.4Moderate
252.4Moderate
262.3Moderate
272.3Moderate
282.2Moderate
292.2Moderate
302.1Moderate
Planning a trip in September

Is September a good time to visit Karlskrona?

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

4.9
Sightseeing
4th-best month of the year
0.7
Beach & pool
4th-best month of the year

September is a reasonable time to visit Karlskrona for sightseeing.

What to pack for Karlskrona in September

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

In September, Karlskrona sees daytime highs around 16°C and nights near 11°C. Worth packing: a warm layer and rain gear. About 10 days see rain.

a warm layerrain gear

Sea temperature near Karlskrona in September

The nearest coast averages about 15°C in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea offshore is warmest in August at about 18°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°5°10°15°20°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshing
Sea temperature (°C)Comfort
Jan4Bracing
Feb3Bracing
Mar3Bracing
Apr5Bracing
May8Bracing
Jun13Bracing
Jul17Cool
Aug18Cool
Sep15Cool
Oct12Bracing
Nov8Bracing
Dec6Bracing

UV index in Karlskrona in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 3 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Karlskrona peaks around June 18 at about 5 (high) — a little sun protection helps at midday. 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 5Dec 20UV 0
UV index (midday)Level
Jan0Low
Feb1Low
Mar2Moderate
Apr3Moderate
May5Moderate
Jun5High
Jul5Moderate
Aug5Moderate
Sep3Moderate
Oct1Low
Nov1Low
Dec0Low
Location & terrain

Where is Karlskrona?

Karlskrona sits at 56.2°N, 15.6°E, 18 m above sea level, in Sweden. The nearest listed city is Karlshamn, 45 km away.

VäxjöHässleholmLjungbyOskarshamnYstad

Topography around Karlskrona

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

Within 3 km, the terrain around Karlskrona has only modest variations in elevation — a maximum elevation change of 36 m around an average of 3 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 124 m; within 80 km, significant variations in elevation — a maximum elevation change of 276 m.

The land around Karlskrona is covered by water (76%) within 3 km, water (42%) and trees (40%) within 16 km, and water (47%) and trees (43%) within 80 km.

3 km
36 m
16 km
124 m
80 km
276 m
treesgrasslandcroplandartificial surfaceswaterwetland
September weather nearby: Karlshamn 45 km · Kalmar 73 km · Kristianstad 90 km · Växjö 93 km · Hässleholm 113 km · Ljungby 126 km · Oskarshamn 133 km · Ystad 137 km

Sweden travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / F
230 V · 50 Hz
Prices
≈ 87% of US
price level, 2025
GDP per capita
$63,133
2025
Happiness
7.3 / 10
World Happiness, 2025
Safe drinking water
100%
of population, 2024
Homicide rate
1.1
per 100k, 2023
Road deaths
3.1
per 100k/yr, 2019
Income group
High
World Bank
English
Very high
EF EPI 609
Religion
Church of Sweden 54%none or unspecified 37%other 9%

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 Karlskrona (56.1616°, 15.5866°, elevation 18 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. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).