Södertälje weather in September

In September, Södertälje sees average daytime highs of 16°C and overnight lows near 8°C, with 51 mm of rain across 8.7 wet days and about 12.6 hours of daylight. It is the 4th-warmest and 4th-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 54 min at the start of September to 11 h 18 min by month's end. Set against the rest of the year, September is Södertälje's 5th-clearest and 7th-windiest month. For the whole year in context, see Södertälje's year-round climate.

Daytime high
16°
4th warmest
Overnight low
9th coldest
Rainfall
51 mm
8.7 wet days
Daylight
12 h 30 min
5:28 AM – 5:59 PM
Cloud cover
65%
5th clearest
Wind
13 km/h
7th windiest
Solar energy
2.66 kWh/m²
Travel score
4.9
out of 10

Södertälje is urban area in Södertälje Municipality, Sweden.

Air quality
Good
PM10 19.8 µg/m³ · 2019
Founded
1300

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 Södertälje reaches about 16°C in the afternoon and slips back to 8°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 12°C and 20°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)
11810
21810
31810
41810
51810
61810
71710
8179
9179
10179
11179
12179
13169
14169
15168
16168
17168
18158
19158
20158
21158
22157
23157
24147
25147
26147
27147
28147
29136
30136

How September really feels in Södertälje

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.

Södertälje weather by month

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

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -4°368.15.46.60.0
Feb / -5°307.56.18.80.0
Mar / -3°307.74.611.30.2
Apr10° / 338.11.514.12.2
May15° / 459.60.216.64.6
Jun19° / 10°6611.4018.15.8
Jul22° / 13°7111.5017.56.3
Aug21° / 12°7012.1015.26.0
Sep16° / 518.7012.64.9
Oct10° / 499.50.29.82.2
Nov / 469.92.87.30.2
Dec / -3°4410.45.65.90.0

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 18% of September, with mostly cloudy or overcast conditions the remaining 62%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
13862
23862
33763
43862
53961
64060
74060
83961
94060
104060
114159
123961
133961
144060
154060
164060
173961
183961
193961
203961
213862
223862
233862
243763
253763
263664
273763
283763
293664
303664

Chance of precipitation in September

Any precipitation

Södertälje gets around 51 mm of rain over 8.7 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 30% and peaks near 35% on the wettest days.

0%10%20%30%40%50%151015202530
Rain chance (%)
135
235
334
433
533
632
732
831
931
1031
1130
1230
1330
1429
1529
1629
1729
1828
1928
2028
2128
2228
2328
2428
2528
2628
2728
2829
2929
3029

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 90% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
175214
276204
378193
479183
581172
682162
784151
885141
986131
1087121
1189110
1290100
139190
149280
159370
169370
179460
189550
199550
209640
219640
229640
239730
249730
259730
269730
279730
289820
299820
309820

Wind in September

Winds average 13 km/h in September.

Across September, daily wind ranges from about 12 km/h on the calmest days to 13 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
112calm
212light breeze
312light breeze
412light breeze
512light breeze
612light breeze
712light breeze
812light breeze
912light breeze
1013light breeze
1113light breeze
1213light breeze
1313light breeze
1413light breeze
1513light breeze
1613light breeze
1713light breeze
1813light breeze
1913light breeze
2013light breeze
2113light breeze
2213light breeze
2313light breeze
2413light breeze
2513light breeze
2613light breeze
2713light breeze
2813light breeze
2913light breeze
3013light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 h 54 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 156 minutes over September. Sunrise moves from 4:53 AM to 6:01 AM, and sunset from 6:45 PM to 5:16 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.94:536:45
213.84:566:42
313.74:586:39
413.65:006:36
513.55:036:33
613.45:056:30
713.35:076:27
813.25:106:24
913.15:126:21
1013.15:146:18
1113.05:176:15
1212.95:196:12
1312.85:216:09
1412.75:246:06
1512.65:266:02
1612.55:285:59
1712.45:315:56
1812.35:335:53
1912.25:355:50
2012.25:385:47
2112.15:405:44
2212.05:425:41
2311.95:455:38
2411.85:475:35
2511.75:495:32
2611.65:525:29
2711.55:545:26
2811.45:565:23
2911.35:595:20
3011.36:015:16

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 2.66 kWh/m².

For context, solar energy here swings from a low near 0.21 kWh/m² to a high of 5.73 kWh/m² in June across the year — September's 2.66 kWh/m² falls in the middle.

01234151015202530
Solar energy (kWh/m²)Level
13.4Moderate
23.3Moderate
33.3Moderate
43.2Moderate
53.2Moderate
63.1Moderate
73.1Moderate
83.0Moderate
93.0Moderate
102.9Moderate
112.9Moderate
122.8Moderate
132.8Moderate
142.7Moderate
152.7Moderate
162.6Moderate
172.6Moderate
182.5Moderate
192.5Moderate
202.4Moderate
212.4Moderate
222.3Moderate
232.3Moderate
242.2Moderate
252.2Moderate
262.1Moderate
272.1Moderate
282.0Moderate
292.0Dim
301.9Dim
Planning a trip in September

Is September a good time to visit Södertälje?

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
0.8
Beach & pool
4th-best month of the year

September is a reasonable time to visit Södertälje for sightseeing.

What to pack for Södertälje in September

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

In September, Södertälje sees daytime highs around 16°C and nights near 8°C. Worth packing: a warm layer and rain gear. About 9 days see rain.

a warm layerrain gear

Sea temperature near Södertälje in September

The nearest coast averages about 14°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 38 km away) is warmest in August at about 17°C and coldest in March 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
Mar2Bracing
Apr3Bracing
May7Bracing
Jun12Bracing
Jul16Cool
Aug17Cool
Sep14Bracing
Oct10Bracing
Nov7Bracing
Dec5Bracing

UV index in Södertälje in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 3. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Södertälje peaks around June 17 at about 5 (high) — a little sun protection helps at midday. It bottoms out near December 19 at about 0 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 4 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateModerateLowJun 17UV 5Dec 19UV 0
UV index (midday)Level
Jan0Low
Feb1Low
Mar2Low
Apr3Moderate
May4Moderate
Jun5High
Jul5Moderate
Aug4Moderate
Sep3Moderate
Oct1Low
Nov0Low
Dec0Low
Location & terrain

Where is Södertälje?

Södertälje sits at 59.2°N, 17.6°E, 29 m above sea level, in Sweden. The nearest listed city is Tumba, 12 km away.

Topography around Södertälje

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

Within 3 km, the terrain around Södertälje has only modest variations in elevation — a maximum elevation change of 81 m around an average of 41 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 105 m; within 80 km, only modest variations in elevation — a maximum elevation change of 135 m.

The land around Södertälje is covered by trees (52%) and artificial surfaces (34%) within 3 km, trees (57%) and water (20%) within 16 km, and trees (44%) and water (36%) within 80 km.

3 km
81 m
16 km
105 m
80 km
135 m
treesgrasslandcroplandartificial surfaceswaterwetland
September weather nearby: Tumba 12 km · Ekerö 15 km · Tullinge 16 km · Huddinge 21 km · Hässelby Villastad 23 km · Bromma 24 km · Årsta 27 km · Sundbyberg 27 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 Södertälje (59.1955°, 17.6253°, elevation 29 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).