Larvik weather in September

In September, Larvik sees average daytime highs of 15°C and overnight lows near 12°C, with 100 mm of rain across 10.9 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 29% 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 Larvik's 6th-clearest and 6th-windiest month. For the whole year in context, see Larvik's year-round climate.

Daytime high
15°
4th warmest
Overnight low
12°
9th coldest
Rainfall
100 mm
10.9 wet days
Daylight
12 h 30 min
5:59 AM – 6:30 PM
Cloud cover
61%
6th clearest
Wind
19 km/h
6th windiest
Solar energy
2.74 kWh/m²
Travel score
4.6
out of 10

Larvik is city in Larvik Municipality, Norway.

Density
1,697/km²
people per km²
Founded
1671

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 Larvik reaches about 15°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 13°C and 18°C. Set against its neighbours, September runs about 3°C cooler than August and about 5°C warmer than October.

10°15°20°151015202530
Avg high (°C)Avg low (°C)
11713
21713
31713
41713
51713
61713
71713
81613
91612
101612
111612
121612
131612
141612
151612
161512
171511
181511
191511
201511
211511
221511
231411
241411
251410
261410
271410
281410
291310
301310

How September really feels in Larvik

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.

Larvik 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 / -1°8612.17.76.70.0
Feb / -1°599.46.88.80.0
Mar / 578.44.711.40.1
Apr / 518.31.314.11.6
May13° / 618.80.216.53.8
Jun17° / 12°779.90185.3
Jul19° / 15°759.3017.46.3
Aug19° / 15°9311.9015.25.9
Sep15° / 12°10010.9012.64.6
Oct11° / 11413.30.59.82.4
Nov / 11213.62.87.40.6
Dec / 85134.760.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 29% 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 55%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14852
24852
34852
44753
54753
64753
74753
84654
94753
104654
114654
124555
134654
144555
154555
164456
174456
184357
194357
204357
214357
224357
234357
244357
254357
264357
274357
284258
294357
304258

Chance of precipitation in September

Any precipitation

Larvik gets around 100 mm of rain over 10.9 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 37% and peaks near 38% on the wettest days.

0%10%20%30%40%50%151015202530
Rain chance (%)
138
238
337
437
537
637
737
837
937
1038
1138
1238
1338
1437
1537
1637
1737
1836
1936
2036
2136
2236
2336
2436
2536
2636
2737
2837
2937
3038

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
479192
579192
680182
780182
882171
982171
1083161
1184151
1285141
1386131
1487121
1588111
1689101
1789101
189091
199280
209280
219370
229370
239460
249460
259550
269550
279640
289640
299640
309730

Wind in September

Winds average 19 km/h in September.

Across September, daily wind ranges from about 17 km/h on the calmest days to 20 km/h at its breeziest. It stays fairly steady from day to day.

0510152025151015202530
Wind speed (km/h)Feels
117light breeze
218light breeze
318light breeze
418light breeze
518light breeze
618light breeze
718light breeze
819light breeze
919light breeze
1019light breeze
1119light breeze
1219light breeze
1319light breeze
1419light breeze
1519light breeze
1619light breeze
1719light breeze
1819light breeze
1919light breeze
2019light breeze
2119light breeze
2219light breeze
2319light breeze
2419light breeze
2519light breeze
2619light breeze
2719light breeze
2819light breeze
2920light breeze
3020light 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 5:24 AM to 6:31 AM, and sunset from 7:15 PM to 5:47 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.95:247:15
213.85:267:12
313.75:297:09
413.65:317:06
513.55:337:03
613.45:367:00
713.35:386:57
813.25:406:54
913.15:436:51
1013.15:456:48
1113.05:476:45
1212.95:496:42
1312.85:526:39
1412.75:546:36
1512.65:566:33
1612.55:596:30
1712.46:016:27
1812.36:036:24
1912.26:066:20
2012.26:086:17
2112.16:106:14
2212.06:136:11
2311.96:156:08
2411.86:176:05
2511.76:206:02
2611.66:225:59
2711.56:245:56
2811.46:275:53
2911.36:295:50
3011.36:315:47

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 2.74 kWh/m².

For context, solar energy here swings from a low near 0.24 kWh/m² to a high of 6.06 kWh/m² in June across the year — September's 2.74 kWh/m² falls in the middle.

01234151015202530
Solar energy (kWh/m²)Level
13.5Moderate
23.5Moderate
33.4Moderate
43.4Moderate
53.3Moderate
63.3Moderate
73.2Moderate
83.1Moderate
93.1Moderate
103.0Moderate
113.0Moderate
122.9Moderate
132.9Moderate
142.8Moderate
152.8Moderate
162.7Moderate
172.6Moderate
182.6Moderate
192.5Moderate
202.5Moderate
212.5Moderate
222.4Moderate
232.4Moderate
242.3Moderate
252.2Moderate
262.2Moderate
272.1Moderate
282.1Moderate
292.0Moderate
302.0Moderate
Planning a trip in September

Is September a good time to visit Larvik?

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
0.5
Beach & pool
4th-best month of the year

September is a reasonable time to visit Larvik for sightseeing.

What to pack for Larvik in September

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

In September, Larvik sees daytime highs around 15°C and nights near 12°C. Worth packing: a warm layer and rain gear. About 11 days see rain.

a warm layerrain gear

Sea temperature near Larvik 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 20 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
Jan5Bracing
Feb3Bracing
Mar4Bracing
Apr6Bracing
May11Bracing
Jun15Bracing
Jul17Cool
Aug18Cool
Sep15Cool
Oct12Bracing
Nov9Bracing
Dec6Bracing

UV index in Larvik 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 Larvik peaks around July 20 at about 5 (moderate) — 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.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateLowJul 20UV 5Dec 19UV 0
UV index (midday)Level
Jan0Low
Feb1Low
Mar2Low
Apr3Moderate
May4Moderate
Jun4Moderate
Jul5Moderate
Aug5Moderate
Sep3Moderate
Oct1Low
Nov0Low
Dec0Low
Location & terrain

Where is Larvik?

Larvik sits at 59.1°N, 10.0°E, 49 m above sea level, in Norway. The nearest listed city is Sandefjord, 14 km away.

Topography around Larvik

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

Within 3 km, the terrain around Larvik has only modest variations in elevation — a maximum elevation change of 173 m around an average of 44 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 319 m; within 80 km, large variations in elevation — a maximum elevation change of 1,191 m.

The land around Larvik is covered by trees (40%), water (25%) and artificial surfaces (20%) within 3 km, trees (44%) and water (39%) within 16 km, and trees (53%) and water (38%) within 80 km.

3 km
173 m
16 km
319 m
80 km
1,191 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Sandefjord 14 km · Porsgrunn 24 km · Skien 30 km · Tønsberg 32 km · Horten 48 km · Fredrikstad 54 km · Moss 55 km · Sarpsborg 66 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 Larvik (59.0533°, 10.0352°, elevation 49 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).