Slagelse weather in September

In September, Slagelse sees average daytime highs of 16°C and overnight lows near 12°C, with 60 mm of rain across 10.4 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 18°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 36 min at the start of September to 11 h 24 min by month's end. Set against the rest of the year, September is Slagelse's 6th-clearest and 7th-windiest month. For the whole year in context, see Slagelse's year-round climate.

Daytime high
16°
4th warmest
Overnight low
12°
10th coldest
Rainfall
60 mm
10.4 wet days
Daylight
12 h 24 min
5:55 AM – 6:22 PM
Cloud cover
66%
6th clearest
Wind
20 km/h
7th windiest
Solar energy
3.03 kWh/m²
Travel score
5.0
out of 10

Slagelse is town in Denmark.

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 15°C by the end.

A typical September day in Slagelse reaches about 16°C in the afternoon and slips back to 12°C overnight — a 4°C spread between the day's warmth and the night's chill. On most days the high lands between 14°C and 20°C. Set against its neighbours, September runs about 4°C cooler than August and about 4°C warmer than October.

10°15°20°25°151015202530
Avg high (°C)Avg low (°C)
11814
21814
31814
41814
51813
61813
71813
81713
91713
101713
111713
121713
131713
141712
151712
161612
171612
181612
191612
201612
211612
221612
231612
241511
251511
261511
271511
281511
291511
301411

How September really feels in Slagelse

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.

Slagelse 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 / 5712.33.87.50.0
Feb / 449.73.69.20.0
Mar / 4510.22.211.40.3
Apr10° / 3790.413.82.2
May14° / 5210.2015.94.2
Jun18° / 12°6510.8017.15.5
Jul20° / 15°6711.1016.66.2
Aug20° / 15°6911.5014.86.1
Sep16° / 12°6010.4012.55.0
Oct12° / 6712.2010.12.9
Nov / 5812.30.88.11.0
Dec / 5911.92.36.90.0

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 20% of September, with mostly cloudy or overcast conditions the remaining 61%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14357
24357
34258
44258
54258
64258
74258
84159
94159
104159
114159
124060
134060
144060
153961
163961
173961
183961
193961
203862
213862
223862
233862
243862
253664
263664
273664
283664
293763
303763

Chance of precipitation in September

Any precipitation

Slagelse 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 35% and peaks near 37% on the wettest days.

0%10%20%30%40%50%151015202530
Rain chance (%)
137
237
337
437
536
636
736
836
935
1035
1135
1235
1335
1435
1535
1635
1734
1834
1934
2034
2134
2234
2334
2435
2535
2635
2736
2836
2937
3037

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 76% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)
1573571
2593461
3623350
4623350
5643240
6653140
7673030
8682930
9692830
10702730
11722620
12732520
13742420
14752320
15782110
16792010
17801910
18811810
19821710
20831700
21841600
22851500
23851500
24861400
25871300
26871300
27881200
28881200
29891100
30901000

Wind in September

Winds average 20 km/h in September.

Across September, daily wind ranges from about 19 km/h on the calmest days to 21 km/h at its breeziest. It stays fairly steady from day to day.

0510152025151015202530
Wind speed (km/h)Feels
119light breeze
219light breeze
320light breeze
420light breeze
520light breeze
620light breeze
720breezy
820breezy
920breezy
1020breezy
1120breezy
1221breezy
1321breezy
1421breezy
1521breezy
1621breezy
1721breezy
1820breezy
1920breezy
2020breezy
2120breezy
2220breezy
2320breezy
2420breezy
2520breezy
2620breezy
2721breezy
2821breezy
2921breezy
3021breezy

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 h 36 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 132 minutes over September. Sunrise moves from 5:26 AM to 6:23 AM, and sunset from 7:02 PM to 5:45 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.65:267:02
213.55:287:00
313.55:306:57
413.45:326:55
513.35:346:52
613.25:366:49
713.15:386:47
813.15:406:44
913.05:426:41
1012.95:446:39
1112.85:466:36
1212.85:486:33
1312.75:506:30
1412.65:526:28
1512.55:536:25
1612.45:556:22
1712.45:576:20
1812.35:596:17
1912.26:016:14
2012.16:036:12
2112.16:056:09
2212.06:076:06
2311.96:096:03
2411.86:116:01
2511.76:135:58
2611.76:155:55
2711.66:175:53
2811.56:195:50
2911.46:215:47
3011.46:235:45

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.03 kWh/m².

For context, solar energy here swings from a low near 0.4 kWh/m² to a high of 6.04 kWh/m² in June across the year — September's 3.03 kWh/m² falls in the middle.

01234151015202530
Solar energy (kWh/m²)Level
13.8Moderate
23.7Moderate
33.7Moderate
43.6Moderate
53.6Moderate
63.5Moderate
73.5Moderate
83.4Moderate
93.4Moderate
103.3Moderate
113.3Moderate
123.2Moderate
133.1Moderate
143.1Moderate
153.0Moderate
163.0Moderate
172.9Moderate
182.9Moderate
192.8Moderate
202.8Moderate
212.7Moderate
222.7Moderate
232.6Moderate
242.6Moderate
252.5Moderate
262.5Moderate
272.4Moderate
282.4Moderate
292.3Moderate
302.3Moderate
Planning a trip in September

Is September a good time to visit Slagelse?

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 Slagelse for sightseeing.

What to pack for Slagelse in September

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

In September, Slagelse sees daytime highs around 16°C and nights near 12°C. Worth packing: a warm layer, rain gear and a windbreaker. About 10 days see rain.

a warm layerrain geara windbreaker

Sea temperature near Slagelse in September

The nearest coast averages about 16°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 15 km away) is warmest in August at about 18°C and coldest in February near 2°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
Jan3Bracing
Feb2Bracing
Mar3Bracing
Apr5Bracing
May11Bracing
Jun15Bracing
Jul18Cool
Aug18Cool
Sep16Cool
Oct12Bracing
Nov8Bracing
Dec5Bracing

UV index in Slagelse 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 Slagelse peaks around June 22 at about 6 (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 22UV 6Dec 20UV 0
UV index (midday)Level
Jan0Low
Feb1Low
Mar2Moderate
Apr3Moderate
May5Moderate
Jun6High
Jul6High
Aug5Moderate
Sep4Moderate
Oct2Low
Nov1Low
Dec0Low
Location & terrain

Where is Slagelse?

Slagelse sits at 55.4°N, 11.4°E, 51 m above sea level, in Denmark. The nearest listed city is Klinteby Frihed, 28 km away.

Klinteby FrihedRingstedNæstvedKalundborgNyborgHolbækKøgeRoskilde

Topography around Slagelse

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

Within 3 km, the terrain around Slagelse has only modest variations in elevation — a maximum elevation change of 90 m around an average of 47 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 111 m; within 80 km, only modest variations in elevation — a maximum elevation change of 145 m.

The land around Slagelse is covered by artificial surfaces (30%), grassland (24%) and cropland (24%) within 3 km, cropland (50%) within 16 km, and water (49%) and cropland (29%) within 80 km.

3 km
90 m
16 km
111 m
80 km
145 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Klinteby Frihed 28 km · Ringsted 28 km · Næstved 32 km · Kalundborg 35 km · Nyborg 37 km · Holbæk 42 km · Køge 53 km · Roskilde 53 km

Denmark travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / E / F / K
230 V · 50 Hz
Prices
≈ 92% of US
price level, 2025
GDP per capita
$76,970
2025
Happiness
7.5 / 10
World Happiness, 2025
Safe drinking water
100%
of population, 2024
Homicide rate
0.8
per 100k, 2023
Road deaths
3.7
per 100k/yr, 2019
Income group
High
World Bank
English
Very high
EF EPI 611
Religion
Evangelical Lutheran 71%other/none/unspecified 24%Muslim 4%

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 Slagelse (55.4028°, 11.3546°, elevation 51 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).