Tromso weather in September

In September, Tromso sees average daytime highs of 10°C and overnight lows near 5°C, with 125 mm of precipitation across 17.2 wet days and about 12.9 hours of daylight. It is the 4th-warmest and 2nd-wettest month of the year here.

Highs ease over the month, from about 12°C in the first days to 8°C by the end. The sky is clear or mostly clear about 13% of the time in September, and the air most often feels dry.

Daylight stretches from about 15 hours at the start of September to 10 h 48 min by month's end. Set against the rest of the year, September is Tromso's 7th-clearest and 9th-windiest month. For the whole year in context, see Tromso's year-round climate.

Daytime high
10°
4th warmest
Overnight low
9th coldest
Precipitation
125 mm
17.2 wet days
Daylight
12 h 48 min
5:13 AM – 6:04 PM
Cloud cover
76%
7th clearest
Wind
9 km/h
9th windiest
Solar energy
1.57 kWh/m²
Travel score
2.0
out of 10

Tromso is city in Tromsø municipality, Norway.

Air quality
Good
PM2.5 6.3 µg/m³ · 2019
Density
1,972/km²
people per km²
Founded
1794

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 12°C in the first days to 8°C by the end.

A typical September day in Tromso reaches about 10°C in the afternoon and slips back to 5°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between 6°C and 15°C. Set against its neighbours, September runs about 4°C cooler than August and about 6°C warmer than October.

-5°10°15°20°151015202530
Avg high (°C)Avg low (°C)
1137
2137
3137
4127
5127
6127
7127
8126
9126
10126
11116
12116
13116
14116
15115
16115
17105
18105
19105
20105
21105
2294
2394
2494
2594
2694
2784
2883
2983
3083

How September really feels in Tromso

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.

Tromso weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan-4° / -10°10514.715.20.80.0
Feb-4° / -10°9114.114.66.40.0
Mar-1° / -7°10215.616.310.90.0
Apr / -3°8514.612.715.50.0
May / 9116.16.921.11.1
Jun12° / 9315.20.6242.6
Jul15° / 9014.2023.34.0
Aug14° / 10215.3017.63.6
Sep10° / 12517.21.312.92.0
Oct / 12816.98.88.40.2
Nov-0° / -5°951512.22.70.0
Dec-3° / -8°10315.414.900.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 13% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 10% of September, with mostly cloudy or overcast conditions the remaining 77%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
12080
22080
32080
42080
52080
62080
72179
82179
92179
102179
112179
122278
132278
142278
152278
162278
172377
182476
192476
202377
212377
222377
232476
242575
252575
262674
272773
282773
292872
302971

Chance of precipitation in September

Any precipitationSnow

Tromso gets around 125 mm of rain and snow over 17.2 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 56% and peaks near 58% on the wettest days, and about 1 day brings snow.

0%20%40%60%151015202530
Rain chance (%)Snow chance (%)
1570
2580
3580
4580
5580
6581
7581
8571
9571
10571
11561
12561
13562
14552
15553
16563
17564
18564
19565
20576
21576
22567
23568
24569
25559
265510
275410
285411
295312
305312

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 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)
1991
2991
3991
4991
51000
61000
71000
81000
91000
101000
111000
121000
131000
141000
151000
161000
171000
181000
191000
201000
211000
221000
231000
241000
251000
261000
271000
281000
291000
301000

Wind in September

Winds average 9 km/h in September.

Across September, daily wind ranges from about 9 km/h on the calmest days to 9 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
19calm
29calm
39calm
49calm
59calm
69calm
79calm
89calm
99calm
109calm
119calm
129calm
139calm
149calm
159calm
169calm
179calm
189calm
199calm
209calm
219calm
229calm
239calm
249calm
259calm
269calm
279calm
289calm
299calm
309calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 15 hours at the start of September to 10 h 48 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 252 minutes over September. Sunrise moves from 4:12 AM to 6:09 AM, and sunset from 7:15 PM to 4:58 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
115.04:127:15
214.94:177:10
314.74:217:06
414.64:257:01
514.44:296:56
614.34:336:51
714.24:376:46
814.04:416:42
913.94:456:37
1013.74:496:32
1113.64:536:27
1213.44:576:23
1313.35:016:18
1413.15:056:13
1513.05:096:08
1612.85:136:04
1712.75:175:59
1812.55:215:54
1912.45:255:49
2012.35:295:45
2112.15:335:40
2212.05:375:35
2311.85:415:30
2411.75:455:26
2511.55:495:21
2611.45:535:16
2711.25:575:12
2811.16:015:07
2910.96:055:02
3010.86:094:58

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 1.57 kWh/m².

For context, solar energy here swings from a low near 0 kWh/m² to a high of 4.65 kWh/m² in June across the year — September's 1.57 kWh/m² falls in the middle.

0123151015202530
Solar energy (kWh/m²)Level
12.2Moderate
22.1Moderate
32.1Moderate
42.0Moderate
52.0Moderate
62.0Dim
71.9Dim
81.9Dim
91.8Dim
101.8Dim
111.8Dim
121.7Dim
131.7Dim
141.6Dim
151.6Dim
161.6Dim
171.5Dim
181.5Dim
191.4Dim
201.4Dim
211.4Dim
221.3Dim
231.3Dim
241.3Dim
251.2Dim
261.2Dim
271.1Dim
281.1Dim
291.1Dim
301.1Dim
Planning a trip in September

Is September a good time to visit Tromso?

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

2.0
Sightseeing
4th-best month of the year
Beach & pool
never really warm enough

September is a weaker month for outdoor sightseeing in Tromso.

What to pack for Tromso in September

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

In September, Tromso sees daytime highs around 10°C and nights near 5°C. Pack a warm layer and rain gear. About 17 days see rain.

a warm layerrain gear

Sea temperature near Tromso in September

The nearest coast averages about 10°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 28 km away) is warmest in August at about 11°C and coldest in March near 4°C.

The water stays below 20°C all year — cool enough that most swimmers want a wetsuit.

5°10°JanFebMarAprMayJunJulAugSepOctNovDecbracing
Sea temperature (°C)Comfort
Jan5Bracing
Feb5Bracing
Mar4Bracing
Apr4Bracing
May6Bracing
Jun8Bracing
Jul10Bracing
Aug11Bracing
Sep10Bracing
Oct9Bracing
Nov7Bracing
Dec6Bracing

UV index in Tromso in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 1. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Tromso peaks around July 15 at about 4 (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 2 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateLowJul 15UV 4Jan 1UV 0
UV index (midday)Level
Jan0Low
Feb0Low
Mar1Low
Apr2Low
May3Moderate
Jun3Moderate
Jul4Moderate
Aug3Moderate
Sep1Low
Oct0Low
Nov0Low
Dec0Low
Location & terrain

Where is Tromso?

Tromso sits at 69.6°N, 19.0°E, in Norway. The nearest listed city is Tromsdalen, 2.0 km away.

AltaKirunaLofotenLeviBodøMo i Rana

Topography around Tromso

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

Within 3 km, the terrain around Tromso has large variations in elevation — a maximum elevation change of 641 m around an average of 68 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,225 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,831 m.

The land around Tromso is covered by trees (39%) and water (37%) within 3 km, grassland (36%), water (26%) and trees (20%) within 16 km, and water (43%) and grassland (21%) within 80 km.

3 km
641 m
16 km
1,225 m
80 km
1,831 m
treesgrasslandartificial surfacesbare terrainsnow and icewaterwetlandmoss and lichen
September weather nearby: Tromsdalen 2.0 km · Harstad 134 km · Alta 169 km · Kiruna 206 km · Lofoten 235 km · Levi 312 km · Bodø 323 km · Mo i Rana 421 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 Tromso (69.6489°, 18.9551°), 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).