Sandefjord weather in September

In September, Sandefjord sees average daytime highs of 15°C and overnight lows near 10°C, with 109 mm of rain across 11.3 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 13°C by the end. The sky is clear or mostly clear about 27% 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 Sandefjord's 6th-clearest and 6th-windiest month. For the whole year in context, see Sandefjord's year-round climate.

Daytime high
15°
4th warmest
Overnight low
10°
9th coldest
Rainfall
109 mm
11.3 wet days
Daylight
12 h 30 min
5:58 AM – 6:29 PM
Cloud cover
62%
6th clearest
Wind
14 km/h
6th windiest
Solar energy
2.63 kWh/m²
Travel score
4.5
out of 10

Sandefjord is city within Sandefjord Municipality, Norway.

Density
2,673/km²
people per km²
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 17°C in the first days to 13°C by the end.

A typical September day in Sandefjord reaches about 15°C in the afternoon and slips back to 10°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between 12°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)
11812
21712
31712
41712
51712
61711
71711
81711
91611
101611
111611
121611
131611
141610
151610
161510
171510
181510
191510
201510
211510
22149
23149
24149
25149
26149
27149
28139
29138
30138

How September really feels in Sandefjord

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.

Sandefjord 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 / -3°8812.29.16.60.0
Feb / -3°619.27.48.80.0
Mar / -1°608.75.511.30.2
Apr / 568.61.914.12.0
May14° / 7010.10.516.64.2
Jun18° / 11°8811.60185.5
Jul20° / 14°9111.5017.46.1
Aug19° / 14°9913.1015.25.8
Sep15° / 10°10911.3012.64.5
Oct10° / 11813.10.99.82.1
Nov / 115144.27.40.3
Dec / -1°8712.76.760.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 27% 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 57%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14654
24753
34654
44654
54555
64456
74555
84456
94555
104456
114456
124357
134456
144456
154456
164456
174357
184357
194357
204258
214258
224258
234159
244159
254159
264060
274060
284060
294060
303862

Chance of precipitation in September

Any precipitation

Sandefjord gets around 109 mm of rain over 11.3 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 38% and peaks near 39% on the wettest days.

0%10%20%30%40%50%151015202530
Rain chance (%)
139
239
338
438
538
638
738
839
939
1039
1139
1239
1339
1439
1539
1639
1738
1838
1938
2038
2137
2237
2337
2437
2538
2638
2738
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 90% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
180182
281172
381172
483161
584151
684151
785141
886131
986131
1088120
1188120
1289110
1390100
1490100
159190
169280
179370
189370
199460
209460
219460
229550
239550
249550
259640
269640
279640
289730
299730
309820

Wind in September

Winds average 14 km/h in September.

Across September, daily wind ranges from about 13 km/h on the calmest days to 14 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
113light breeze
213light breeze
313light breeze
413light breeze
513light breeze
613light breeze
713light breeze
814light breeze
914light breeze
1014light breeze
1114light breeze
1214light breeze
1314light breeze
1414light breeze
1514light breeze
1614light breeze
1714light breeze
1814light breeze
1914light breeze
2014light breeze
2114light breeze
2214light breeze
2314light breeze
2414light breeze
2514light breeze
2614light breeze
2714light breeze
2814light breeze
2914light breeze
3014light 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 5:23 AM to 6:31 AM, and sunset from 7:15 PM to 5:46 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.95:237:15
213.85:257:12
313.75:287:09
413.65:307:06
513.55:327:03
613.45:357:00
713.35:376:57
813.25:396:53
913.15:426:50
1013.15:446:47
1113.05:466:44
1212.95:496:41
1312.85:516:38
1412.75:536:35
1512.65:566:32
1612.55:586:29
1712.46:006:26
1812.36:036:23
1912.26:056:20
2012.26:076:17
2112.16:106:14
2212.06:126:11
2311.96:146:08
2411.86:176:04
2511.76:196:01
2611.66:215:58
2711.56:245:55
2811.46:265:52
2911.36:285:49
3011.36:315:46

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 5.79 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
73.1Moderate
83.0Moderate
93.0Moderate
102.9Moderate
112.8Moderate
122.8Moderate
132.7Moderate
142.7Moderate
152.6Moderate
162.6Moderate
172.5Moderate
182.5Moderate
192.4Moderate
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 Sandefjord?

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

4.5
Sightseeing
4th-best month of the year
0.5
Beach & pool
4th-best month of the year

September is a reasonable time to visit Sandefjord for sightseeing.

What to pack for Sandefjord in September

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

In September, Sandefjord sees daytime highs around 15°C and nights near 10°C. Worth packing: a warm layer and rain gear. About 11 days see rain.

a warm layerrain gear

Sea temperature near Sandefjord 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
Apr6Bracing
May11Bracing
Jun15Bracing
Jul18Cool
Aug18Cool
Sep15Cool
Oct12Bracing
Nov9Bracing
Dec6Bracing

UV index in Sandefjord 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 Sandefjord 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 Sandefjord?

Sandefjord sits at 59.1°N, 10.2°E, 11 m above sea level, in Norway. The nearest listed city is Larvik, 14 km away.

Topography around Sandefjord

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

Within 3 km, the terrain around Sandefjord has only modest variations in elevation — a maximum elevation change of 111 m around an average of 41 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 305 m; within 80 km, large variations in elevation — a maximum elevation change of 1,091 m.

The land around Sandefjord is covered by trees (39%), cropland (21%) and artificial surfaces (21%) within 3 km, trees (45%) and water (31%) within 16 km, and trees (54%) and water (35%) within 80 km.

3 km
111 m
16 km
305 m
80 km
1,091 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Larvik 14 km · Tønsberg 19 km · Porsgrunn 32 km · Horten 35 km · Skien 36 km · Fredrikstad 42 km · Moss 42 km · Sarpsborg 54 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 Sandefjord (59.1312°, 10.2166°, elevation 11 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).