Tromsø weather by month

TL;DR

At the TROMSO weather station, which we use for Tromsø, the warmest month is July (average high 16.3 °C) and the coldest February (average low −5.6 °C), averaged over 1991–2020. The wettest month is October (127 mm of rain). Across Norway, the quietest month for visitors in 2025 was January.

Tromsø from above at twilight in winter
Tromsø from above at twilight in winter. Photo by Efrem Efre on Pexels.

Tromsø weather by month

Averages for 1991–2020 at the TROMSO weather station (100 m above sea level), from the WMO climate normals, next to each month's share of Norway's tourist nights (Eurostat, 2025) in 2025. The shares are for the whole of Norway, not Tromsø alone. These are long-term averages, not a forecast. A rainy day is one with at least 1 mm of rain.

Tromsø: average weather by month, 1991 to 2020, and share of Norway's 2025 visits
MonthAverage highAverage lowRainRainy daysDaylight on the 15thShare of 2025 (Norway)
January−1.0 °C−5.3 °C108 mm15.0 days0 h 50 min4.9%
February−1.1 °C−5.6 °C97 mm13.0 days7 h 30 min5.7%
March0.6 °C−4.4 °C97 mm14.0 days11 h 35 min6.3%
April4.1 °C−1.6 °C71 mm13.0 days16 h 5 min5.9%
May8.8 °C2.4 °C56 mm11.0 days22 h 5 min8.2%
June13.0 °C6.2 °C58 mm11.0 days24 h (the sun does not set)11.9%
July16.3 °C9.1 °C72 mm11.0 days24 h (the sun does not set)18.2%
August15.0 °C8.3 °C88 mm13.0 days18 h 5 min13.6%
September10.9 °C5.3 °C111 mm15.0 days13 h 25 min8.4%
October5.2 °C0.9 °C127 mm16.0 days9 h 10 min6.5%
November2.1 °C−1.9 °C94 mm13.0 days4 h 5 min5.5%
December0.3 °C−3.9 °C110 mm15.0 days0 (the sun does not rise)4.9%

On some 15ths the sun does not rise or set at all at this latitude, so the daylight column says so instead of giving a time.

Golden hour and sea temperature

Evening golden hour is our calculation for the 15th of each month of 2026: the time the sun takes to go from 6° above to 4° below the horizon (there is no official definition). A dash means the band has no evening start or end that day, for example when the sun never climbs 6° above the horizon or never sinks 4° below it. The sea figure is the 1991–2020 average sea surface temperature at the open-sea point nearest the weather station (NOAA OISST).

Tromsø: golden hour and sea temperature by month
MonthEvening golden hour (15th)Sea surface
January–5.4 °C
February2 h 49 min4.5 °C
March1 h 58 min4.1 °C
April2 h 12 min4.3 °C
May–5.8 °C
June–7.8 °C
July–10.1 °C
August2 h 39 min11.0 °C
September1 h 56 min10.0 °C
October2 h 14 min8.6 °C
November–7.4 °C
December–6.3 °C

The quietest and busiest months

In 2025, January was Norway's quietest month (4.9% of the year's tourist nights): at Tromsø's station that month averages a high of −1.0 °C, a low of −5.3 °C and 108 mm of rain. July was the busiest (18.2%): average high 16.3 °C, average low 9.1 °C, 72 mm of rain. The visitor figures are for the whole country, and they do not show that the weather makes a month busier or quieter, so we do not say it does.

What these figures are

One weather station stands for Tromsø; places nearby can differ, especially by height or distance from the sea. For the rest of Norway, including regions and holidays, see our Norway page; for other places, the weather by city list and golden hour by place.

Where the TROMSO weather station is: 69.654° N, 18.937° E. Outline of Norway from Natural Earth (world-atlas), simplified; small islands may not show.

Key takeaways

  • Warmest month: July (average high 16.3 °C); coldest: February (average low −5.6 °C).
  • Wettest month: October (127 mm); driest: May (56 mm).
  • In 2025, January was Norway's quietest month for visitors and July the busiest.

Sources

Weather normals from the WMO 1991–2020 dataset; daylight and golden hour are our calculations; tourism shares are the country's, from Eurostat. See how we research.

  1. Weather: WMO Member Nations (2023). WMO Climatological Standard Normals for 1991-2020 (NCEI Accession 0253808), version 6.6, station TROMSO (station ID 00001026), mean daily maximum and minimum temperature, precipitation and number of days with at least 1 mm of precipitation, normals computed from at least 24 years. NOAA National Centers for Environmental Information. Dataset. doi:10.25921/800j-vn07. Accessed 24 September 2026. Released by NOAA under CC0.
  2. Daylight: our calculation of the time from sunrise to sunset on the 15th of each month of 2026 at the weather station's location, by the method of the NOAA Solar Calculator (NOAA Global Monitoring Laboratory, “Solar Calculation Details”, based on Jean Meeus, Astronomical Algorithms, allowing 0.833° for refraction and the size of the sun). Read it. Checked 22 September 2026. NOAA notes that calculated times can differ from what is observed.
  3. Source: Eurostat, Nights spent at tourist accommodation establishments – monthly data, doi:10.2908/TOUR_OCC_NIM, accessed 25 September 2026. Dataset last updated by Eurostat on 22 September 2026. Extract: number of nights, NACE codes I55.1–I55.3, all guests and split by guests resident in the country and abroad, January–December 2025.
  4. Sea temperature: NOAA Optimum Interpolation Sea Surface Temperature (OISST) v2.1, 0.25° grid, monthly long-term mean 1991–2020 (file sst.mon.ltm.1991-2020.nc). Data provided by the NOAA/OAR/PSL, Boulder, Colorado, USA, from their Web site at https://psl.noaa.gov/. Huang, B., C. Liu, V. Banzon, E. Freeman, G. Graham, B. Hankins, T. Smith and H.-M. Zhang (2021), Improvements of the Daily Optimum Interpolation Sea Surface Temperature (DOISST) Version 2.1, Journal of Climate 34, 2923–2939, doi:10.1175/JCLI-D-20-0166.1. Dataset page. Accessed 24 September 2026. Public domain (NOAA PSL disclaimer). The choice of grid cell and the rounding are ours; these are not official NOAA figures, and NOAA does not endorse this site.

Modified data: the rounding, the arrangement, the daylight, golden-hour and sea columns and the quietest/busiest comparison are ours, from the cited figures.