Fredrikstad weather in September

In September, Fredrikstad sees average daytime highs of 16°C and overnight lows near 9°C, with 81 mm of rain across 10.5 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 18°C in the first days to 14°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 Fredrikstad's 5th-clearest and 6th-windiest month. For the whole year in context, see Fredrikstad's year-round climate.

Daytime high
16°
4th warmest
Overnight low
9th coldest
Rainfall
81 mm
10.5 wet days
Daylight
12 h 30 min
5:55 AM – 6:26 PM
Cloud cover
62%
5th clearest
Wind
14 km/h
6th windiest
Solar energy
2.65 kWh/m²
Travel score
5.0
out of 10

Fredrikstad is settlement in Fredrikstad Municipality, Norway.

Air quality
Good
PM2.5 8.4 µg/m³ · 2019
Density
2,466/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 18°C in the first days to 14°C by the end.

A typical September day in Fredrikstad reaches about 16°C in the afternoon and slips back to 9°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 13°C and 19°C. Set against its neighbours, September runs about 4°C cooler than August and about 6°C warmer than October.

10°15°20°25°151015202530
Avg high (°C)Avg low (°C)
11811
21811
31811
41811
51811
61811
71810
81710
91710
101710
111710
121710
131710
141710
15169
16169
17169
18169
19169
20169
21159
22158
23158
24158
25158
26158
27148
28148
29147
30147

How September really feels in Fredrikstad

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.

Fredrikstad 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°6510.76.36.60.0
Feb / -3°508.55.98.80.0
Mar / -1°458.14.211.30.4
Apr11° / 478.51.214.12.6
May16° / 6110.30.216.64.8
Jun19° / 11°7811.2018.15.9
Jul21° / 13°7711.6017.56.3
Aug20° / 13°8612.4015.26.0
Sep16° / 8110.5012.65.0
Oct11° / 8711.60.69.82.4
Nov / 81122.27.30.4
Dec / -2°7011.44.55.90.0

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
24654
34654
44753
54654
64654
74753
84654
94654
104654
114654
124555
134555
144456
154456
164456
174456
184357
194357
204258
214258
224159
234159
244159
254060
264060
273961
283862
293862
303763

Chance of precipitation in September

Any precipitation

Fredrikstad gets around 81 mm of rain over 10.5 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 36% and peaks near 37% on the wettest days.

0%10%20%30%40%50%151015202530
Rain chance (%)
137
237
336
436
536
636
736
836
937
1037
1137
1237
1336
1436
1536
1636
1735
1835
1935
2035
2134
2234
2334
2434
2534
2634
2735
2835
2936
3036

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 (%)
180173
281163
383152
484142
584142
685132
785132
887121
987121
1088111
1188111
1289101
1389101
149091
159091
169181
179181
189370
199370
209370
219460
229460
239460
249460
259550
269550
279550
289640
299640
309640

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
714light 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 5:20 AM to 6:28 AM, and sunset from 7:12 PM to 5:43 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.95:207:12
213.85:227:09
313.75:257:06
413.65:277:03
513.55:297:00
613.45:326:57
713.35:346:54
813.25:366:51
913.15:396:48
1013.15:416:45
1113.05:436:42
1212.95:466:38
1312.85:486:35
1412.75:506:32
1512.65:536:29
1612.55:556:26
1712.45:576:23
1812.36:006:20
1912.26:026:17
2012.26:046:14
2112.16:076:11
2212.06:096:08
2311.96:116:05
2411.86:146:02
2511.76:165:59
2611.66:185:55
2711.56:215:52
2811.46:235:49
2911.36:265:46
3011.36:285:43

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 2.65 kWh/m².

For context, solar energy here swings from a low near 0.23 kWh/m² to a high of 5.74 kWh/m² in June across the year — September's 2.65 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 Fredrikstad?

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
0.9
Beach & pool
4th-best month of the year

September is a reasonable time to visit Fredrikstad for sightseeing.

What to pack for Fredrikstad in September

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

In September, Fredrikstad sees daytime highs around 16°C and nights near 9°C. Worth packing: a warm layer and rain gear. About 11 days see rain.

a warm layerrain gear

Sea temperature near Fredrikstad 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 Fredrikstad 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 Fredrikstad peaks around June 23 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.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateLowJun 23UV 5Jan 1UV 0
UV index (midday)Level
Jan0Low
Feb1Low
Mar2Low
Apr3Moderate
May4Moderate
Jun5Moderate
Jul5Moderate
Aug5Moderate
Sep3Moderate
Oct1Low
Nov0Low
Dec0Low
Location & terrain

Where is Fredrikstad?

Fredrikstad sits at 59.2°N, 10.9°E, 6 m above sea level, in Norway. The nearest listed city is Sarpsborg, 13 km away.

Topography around Fredrikstad

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

Within 3 km, the terrain around Fredrikstad has only modest variations in elevation — a maximum elevation change of 113 m around an average of 25 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 151 m; within 80 km, large variations in elevation — a maximum elevation change of 863 m.

The land around Fredrikstad is covered by trees (43%) and artificial surfaces (28%) within 3 km, trees (37%) and water (36%) within 16 km, and trees (57%) and water (30%) within 80 km.

3 km
113 m
16 km
151 m
80 km
863 m
treesgrasslandcroplandartificial surfaceswaterwetland
September weather nearby: Sarpsborg 13 km · Halden 28 km · Moss 29 km · Tønsberg 30 km · Horten 34 km · Sandefjord 42 km · Larvik 54 km · Drammen 71 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 Fredrikstad (59.2181°, 10.9298°, elevation 6 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).