Tønsberg weather in September

In September, Tønsberg sees average daytime highs of 16°C and overnight lows near 11°C, with 107 mm of rain across 11.4 wet days and about 12.6 hours of daylight. It is the 4th-warmest and 3rd-wettest month of the year here.

Highs ease over the month, from about 17°C in the first days to 14°C by the end. The sky is clear or mostly clear about 28% 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 Tønsberg's 6th-clearest and 6th-windiest month. For the whole year in context, see Tønsberg's year-round climate.

Daytime high
16°
4th warmest
Overnight low
11°
9th coldest
Rainfall
107 mm
11.4 wet days
Daylight
12 h 30 min
5:57 AM – 6:28 PM
Cloud cover
62%
6th clearest
Wind
15 km/h
6th windiest
Solar energy
2.63 kWh/m²
Travel score
4.6
out of 10

Tønsberg is city in Vestfold county, Norway.

Air quality
Good
PM2.5 6.9 µg/m³ · 2019
Density
5,362/km²
people per km²

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 17°C in the first days to 14°C by the end.

A typical September day in Tønsberg 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 18°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)
11813
21813
31713
41713
51713
61712
71712
81712
91712
101612
111612
121612
131612
141611
151611
161611
171511
181511
191511
201511
211510
221510
231410
241410
251410
261410
271410
28149
29139
30139

How September really feels in Tønsberg

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.

Tønsberg weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 3rd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -2°8212.57.86.60.0
Feb / -2°588.76.38.70.0
Mar / 568.64.511.30.2
Apr / 528.21.214.11.9
May14° / 669.50.216.64.2
Jun18° / 12°8210.4018.15.7
Jul20° / 15°8210.3017.56.3
Aug19° / 15°9112.4015.35.9
Sep16° / 11°10711.4012.64.6
Oct10° / 12012.90.79.82.2
Nov / 1151437.30.4
Dec / -1°8612.95.55.90.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 28% 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 56%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14852
24852
34852
44852
54753
64753
74654
84654
94654
104555
114555
124555
134456
144456
154357
164357
174357
184456
194357
204357
214357
224258
234258
244258
254159
264159
274060
284060
294060
303961

Chance of precipitation in September

Any precipitation

Tønsberg gets around 107 mm of rain over 11.4 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 39% and peaks near 39% on the wettest days.

0%10%20%30%40%50%151015202530
Rain chance (%)
139
238
338
438
538
638
738
838
939
1039
1139
1239
1339
1439
1539
1639
1739
1839
1938
2038
2138
2238
2338
2438
2538
2639
2739
2839
2939
3039

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 (%)
174224
276213
377203
477203
579192
679192
780182
881172
982171
1083161
1184151
1285141
1386131
1487121
1588111
1689101
179091
189091
199181
209370
219370
229460
239460
249460
259550
269550
279640
289640
299640
309730

Wind in September

Winds average 15 km/h in September.

Across September, daily wind ranges from about 14 km/h on the calmest days to 16 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
114light breeze
215light breeze
315light breeze
415light breeze
515light breeze
615light breeze
715light breeze
815light breeze
915light breeze
1015light breeze
1115light breeze
1215light breeze
1315light breeze
1415light breeze
1516light breeze
1615light breeze
1715light breeze
1815light breeze
1915light breeze
2015light breeze
2115light breeze
2215light breeze
2315light breeze
2415light breeze
2515light breeze
2615light breeze
2715light breeze
2816light breeze
2916light breeze
3016light 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 5:22 AM to 6:30 AM, and sunset from 7:14 PM to 5:45 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.95:227:14
213.85:247:11
313.75:277:08
413.65:297:05
513.55:317:02
613.45:346:59
713.35:366:56
813.25:386:53
913.25:416:50
1013.15:436:47
1113.05:456:44
1212.95:486:41
1312.85:506:38
1412.75:526:34
1512.65:556:31
1612.55:576:28
1712.45:596:25
1812.36:026:22
1912.26:046:19
2012.26:066:16
2112.16:096:13
2212.06:116:10
2311.96:146:07
2411.86:166:04
2511.76:186:01
2611.66:215:58
2711.56:235:54
2811.46:255:51
2911.36:285:48
3011.36:305:45

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 2.63 kWh/m².

For context, solar energy here swings from a low near 0.23 kWh/m² to a high of 5.75 kWh/m² in June across the year — September's 2.63 kWh/m² falls in the middle.

01234151015202530
Solar energy (kWh/m²)Level
13.4Moderate
23.3Moderate
33.3Moderate
43.2Moderate
53.2Moderate
63.1Moderate
73.0Moderate
83.0Moderate
92.9Moderate
102.9Moderate
112.8Moderate
122.8Moderate
132.7Moderate
142.7Moderate
152.6Moderate
162.6Moderate
172.5Moderate
182.5Moderate
192.5Moderate
202.4Moderate
212.4Moderate
222.3Moderate
232.3Moderate
242.2Moderate
252.1Moderate
262.1Moderate
272.1Moderate
282.0Moderate
292.0Dim
301.9Dim
Planning a trip in September

Is September a good time to visit Tønsberg?

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

4.6
Sightseeing
4th-best month of the year
0.6
Beach & pool
4th-best month of the year

September is a reasonable time to visit Tønsberg for sightseeing.

What to pack for Tønsberg in September

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

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

a warm layerrain gear

Sea temperature near Tønsberg 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 at the nearest coast (about 16 km away) 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
Apr6Bracing
May11Bracing
Jun15Bracing
Jul18Cool
Aug18Cool
Sep15Cool
Oct12Bracing
Nov9Bracing
Dec6Bracing

UV index in Tønsberg 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 Tønsberg peaks around July 17 at about 5 (moderate) — a little sun protection helps at midday. It bottoms out near January 1 at about 0 (low).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateLowJul 17UV 5Jan 1UV 0
UV index (midday)Level
Jan0Low
Feb1Low
Mar2Low
Apr3Moderate
May4Moderate
Jun5Moderate
Jul5Moderate
Aug5Moderate
Sep3Moderate
Oct1Low
Nov0Low
Dec0Low
Location & terrain

Where is Tønsberg?

Tønsberg sits at 59.3°N, 10.4°E, 16 m above sea level, in Norway. The nearest listed city is Horten, 17 km away.

Topography around Tønsberg

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

Within 3 km, the terrain around Tønsberg has only modest variations in elevation — a maximum elevation change of 101 m around an average of 22 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 222 m; within 80 km, large variations in elevation — a maximum elevation change of 907 m.

The land around Tønsberg is covered by trees (32%) and artificial surfaces (20%) within 3 km, water (38%) and trees (33%) within 16 km, and trees (58%) and water (30%) within 80 km.

3 km
101 m
16 km
222 m
80 km
907 m
treesgrasslandcroplandartificial surfaceswaterwetland
September weather nearby: Horten 17 km · Sandefjord 19 km · Moss 23 km · Fredrikstad 30 km · Larvik 32 km · Sarpsborg 40 km · Porsgrunn 45 km · Skien 46 km

Norway travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type C / F
230 V · 50 Hz
Prices
≈ 91% of US
price level, 2025
GDP per capita
$94,594
2025
Happiness
7.2 / 10
World Happiness, 2025
Safe drinking water
99%
of population, 2024
Homicide rate
0.7
per 100k, 2023
Road deaths
2.1
per 100k/yr, 2019
Income group
High
World Bank
English
Very high
EF EPI 613
Religion
Church of Norway 68%other Christian 4%Muslim 3%Roman Catholic 3%

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 Tønsberg (59.2675°, 10.4076°, elevation 16 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).