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Average Weather in Tromsø Norway

In Tromsø, the summers are short, cool, and mostly cloudy and the winters are long, freezing, windy, and overcast. Over the course of the year, the temperature typically varies from 21°F to 59°F and is rarely below 9°F or above 70°F.

Based on the tourism score, the best time of year to visit Tromsø for warm-weather activities is from mid July to mid August.

Climate Summary

freezingvery coldcoldcoolcoldvery coldJanFebMarAprMayJunJulAugSepOctNovDec44%44%20%20%overcastclearprecipitation: 4.0 inprecipitation: 4.0 in2.1 in2.1 inmuggy: 0%muggy: 0%0%0%drydrytourism score: 3.4tourism score: 3.40.00.0
Click on each chart for more information.

Temperature

The warm season lasts for 2.7 months, from June 14 to September 5, with an average daily high temperature above 53°F. The hottest day of the year is July 24, with an average high of 59°F and low of 48°F.

The cold season lasts for 4.6 months, from November 13 to March 31, with an average daily high temperature below 35°F. The coldest day of the year is January 25, with an average low of 21°F and high of 29°F.

Average High and Low Temperature

The daily average high (red line) and low (blue line) temperature, with 25th to 75th and 10th to 90th percentile bands. The thin dotted lines are the corresponding average perceived temperatures.

The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.

Average Hourly Temperature

Average Hourly Temperature in TromsøJanFebMarAprMayJunJulAugSepOctNovDec12 AM4 AM8 AM12 PM4 PM8 PM12 AMfreezingfreezingvery coldvery coldcoldcool
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
The average hourly temperature, color coded into bands. The shaded overlays indicate night and civil twilight.

Kodiak Station, Alaska, United States (3,627 miles away) is the far-away foreign place with temperatures most similar to Tromsø (view comparison).

Clouds

In Tromsø, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year.

The clearer part of the year in Tromsø begins around April 17 and lasts for 5.3 months, ending around September 28. On May 30, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 44% of the time, and overcast or mostly cloudy 56% of the time.

The cloudier part of the year begins around September 28 and lasts for 6.7 months, ending around April 17. On December 13, the cloudiest day of the year, the sky is overcast or mostly cloudy 80% of the time, and clear, mostly clear, or partly cloudy 20% of the time.

Cloud Cover Categories

Cloud Cover Categories in TromsøclearercloudiercloudierJanFebMarAprMayJunJulAugSepOctNovDec0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%May 3044%May 3044%Dec 1320%Dec 1320%Apr 1732%Apr 1732%Sep 2832%Sep 2832%clearmostly clearpartly cloudymostly cloudyovercast
0% clear 20% mostly clear 40% partly cloudy 60% mostly cloudy 80% overcast 100%
The percentage of time spent in each cloud cover band, categorized by the percentage of the sky covered by clouds.

Precipitation

A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Tromsø varies throughout the year.

The wetter season lasts 5.3 months, from September 3 to February 11, with a greater than 41% chance of a given day being a wet day. The chance of a wet day peaks at 49% on October 21.

The drier season lasts 6.7 months, from February 11 to September 3. The smallest chance of a wet day is 32% on May 29.

Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation in Tromsø changes throughout the year.

Rain alone is the most common for 9.0 months, from March 21 to December 20. The highest chance of a day with rain alone is 45% on September 30.

Snow alone is the most common for 3.0 months, from December 20 to March 21. The highest chance of a day with snow alone is 20% on January 28.

Daily Chance of Precipitation

Daily Chance of Precipitation in TromsøsnowrainJanFebMarAprMayJunJulAugSepOctNovDec0%10%20%30%40%50%60%70%80%90%100%Oct 2149%Oct 2149%May 2932%May 2932%Mar 2136%Mar 2136%Dec 2044%Dec 2044%Sep 341%Sep 341%Feb 1141%Feb 1141%snowmixedrain
The percentage of days in which various types of precipitation are observed, excluding trace quantities: rain alone, snow alone, and mixed (both rain and snow fell in the same day).

Rainfall

To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. Tromsø experiences significant seasonal variation in monthly rainfall.

Rain falls throughout the year in Tromsø. The most rain falls during the 31 days centered around October 9, with an average total accumulation of 3.7 inches.

The least rain falls around March 26, with an average total accumulation of 1.5 inches.

Average Monthly Rainfall

The average rainfall (solid line) accumulated over the course of a sliding 31-day period centered on the day in question, with 25th to 75th and 10th to 90th percentile bands. The thin dotted line is the corresponding average liquid-equivalent snowfall.

Snowfall

We report snowfall in liquid-equivalent terms. The actual depth of new snowfall is typically between 5 and 10 times the liquid-equivalent amount, assuming the ground is frozen. Colder, drier snow tends to be on the higher end of that range and warmer, wetter snow on the lower end.

As with rainfall, we consider the snowfall accumulated over a sliding 31-day period centered around each day of the year. Tromsø experiences significant seasonal variation in monthly liquid-equivalent snowfall.

The snowy period of the year lasts for 7.5 months, from September 29 to May 12, with a sliding 31-day liquid-equivalent snowfall of at least 0.1 inches. The most snow falls during the 31 days centered around January 31, with an average total liquid-equivalent accumulation of 1.7 inches.

The snowless period of the year lasts for 4.6 months, from May 12 to September 29. The least snow falls around July 31, with an average total liquid-equivalent accumulation of 0.0 inches.

Average Liquid-Equivalent Monthly Snowfall

The average liquid-equivalent snowfall (solid line) accumulated over the course of a sliding 31-day period centered on the day in question, with 25th to 75th and 10th to 90th percentile bands. The thin dotted line is the corresponding average rainfall.

Sun

Due to its extreme latitude, Tromsø experiences polar day (also known as the midnight Sun) during the summer and polar night during the winter. These are periods of time in which the sun is continuously above or below the horizon for more than one day. The precise start and end dates of polar day and night vary from year to year and depend on the precise location and elevation of the observer, and the local topography.

In the summer in Tromsø during 2018, the Sun is continuously above the horizon for 2.2 months, rising at 12:51 AM on May 18, and not setting again until 12:44 AM on July 26.

In the winter in Tromsø during 2018, the Sun is continuously below the horizon for 1.6 months, setting at 11:41 AM on November 27, and not rising again until 11:32 AM on January 15.

Hours of Daylight and Twilight

Hours of Daylight and Twilight in Tromsøpolar dayJanFebMarAprMayJunJulAugSepOctNovDec0 hr24 hr4 hr20 hr8 hr16 hr12 hr12 hr16 hr8 hr20 hr4 hr24 hr0 hr12 hr, 17 minMar 2012 hr, 17 minMar 2024 hr, 0 minJun 2124 hr, 0 minJun 2112 hr, 24 minSep 2312 hr, 24 minSep 230 minDec 210 minDec 21nightnightday
The number of hours during which the Sun is visible (black line). From bottom (most yellow) to top (most gray), the color bands indicate: full daylight, twilight (civil, nautical, and astronomical), and full night.

Daylight saving time (DST) is observed in Tromsø during 2018, starting in the spring on March 25, lasting 7.1 months, and ending in the fall on October 28.

Sunrise & Sunset with Twilight and Daylight Saving Time

Sunrise & Sunset with Twilight and Daylight Saving Time in TromsøJanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AMMay 1812:51 AMMay 1812:51 AM12:44 AMJul 2512:44 AMJul 2511:41 AMNov 2711:41 AMNov 27Jan 1511:32 AMJan 1511:32 AMMar 25DSTMar 25DSTdaynightnightnightnightSolarMidnightSolarMidnightSolarNoon
The solar day over the course of the year 2018. From bottom to top, the black lines are the previous solar midnight, sunrise, solar noon, sunset, and the next solar midnight. The day, twilights (civil, nautical, and astronomical), and night are indicated by the color bands from yellow to gray. The transitions to and from daylight saving time are indicated by the 'DST' labels.

Humidity

We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.

The perceived humidity level in Tromsø, as measured by the percentage of time in which the humidity comfort level is muggy, oppressive, or miserable, does not vary significantly over the course of the year, remaining a virtually constant 0% throughout.

Humidity Comfort Levels

Humidity Comfort Levels in TromsøJanFebMarAprMayJunJulAugSepOctNovDec0%10%20%30%40%50%60%70%80%90%100%Jan 190%Jan 190%Jul 210%Jul 210%drydry
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
The percentage of time spent at various humidity comfort levels, categorized by dew point.

Wind

This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.

The average hourly wind speed in Tromsø experiences significant seasonal variation over the course of the year.

The windier part of the year lasts for 6.1 months, from October 23 to April 25, with average wind speeds of more than 8.1 miles per hour. The windiest day of the year is January 30, with an average hourly wind speed of 11.1 miles per hour.

The calmer time of year lasts for 5.9 months, from April 25 to October 23. The calmest day of the year is August 1, with an average hourly wind speed of 5.1 miles per hour.

Average Wind Speed

Average Wind Speed in TromsøwindywindyJanFebMarAprMayJunJulAugSepOctNovDec0 mph2 mph4 mph6 mph8 mph10 mph12 mph14 mph16 mph18 mphJan 3011.1 mphJan 3011.1 mphAug 15.1 mphAug 15.1 mphOct 238.1 mphOct 238.1 mphApr 258.1 mphApr 258.1 mph
The average of mean hourly wind speeds (dark gray line), with 25th to 75th and 10th to 90th percentile bands.

The predominant average hourly wind direction in Tromsø varies throughout the year.

The wind is most often from the east for 2.6 weeks, from May 13 to May 31, with a peak percentage of 30% on May 21. The wind is most often from the west for 2.8 months, from May 31 to August 24, with a peak percentage of 34% on July 19. The wind is most often from the south for 8.6 months, from August 24 to May 13, with a peak percentage of 47% on January 1.

Wind Direction

Wind Direction in TromsøSEWSJanFebMarAprMayJunJulAugSepOctNovDec0%100%20%80%40%60%60%40%80%20%100%0%westsouthnortheast
northeastsouthwest
The percentage of hours in which the mean wind direction is from each of the four cardinal wind directions, excluding hours in which the mean wind speed is less than 1.0 mph. The lightly tinted areas at the boundaries are the percentage of hours spent in the implied intermediate directions (northeast, southeast, southwest, and northwest).

Water Temperature

Tromsø is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.

The average water temperature experiences some seasonal variation over the course of the year.

The time of year with warmer water lasts for 2.4 months, from July 8 to September 21, with an average temperature above 49°F. The day of the year with the warmest water is August 11, with an average temperature of 52°F.

The time of year with cooler water lasts for 4.1 months, from January 9 to May 12, with an average temperature below 41°F. The day of the year with the coolest water is March 24, with an average temperature of 39°F.

Average Water Temperature

The daily average water temperature (purple line), with 25th to 75th and 10th to 90th percentile bands.

Best Time of Year to Visit

To characterize how pleasant the weather is in Tromsø throughout the year, we compute two travel scores.

The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best time of year to visit Tromsø for general outdoor tourist activities is from mid July to mid August, with a peak score in the last week of July.

Tourism Score

Tourism Score in TromsøJanFebMarAprMayJunJulAugSepOctNovDec02468103.43.40.00.0 precipitationprecipitationcloudscloudstemperaturetemperaturetourism score
The tourism score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best time of year to visit Tromsø for hot-weather activities is from mid to late July.

Beach/Pool Score

Beach/Pool Score in TromsøJanFebMarAprMayJunJulAugSepOctNovDec02468100.40.40.00.0precipitationprecipitationcloudsclouds
The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

Methodology

For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.

Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.

Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.

Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.

Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.

Growing Season

Definitions of the growing season vary throughout the world, but for the purposes of this report, we define it as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere).

The growing season in Tromsø typically lasts for 4.3 months (132 days), from around May 16 to around September 25, rarely starting before April 30 or after June 2, and rarely ending before September 4 or after October 14.

Time Spent in Various Temperature Bands and the Growing Season

Time Spent in Various Temperature Bands and the Growing Season in Tromsøgrowing seasonJanFebMarAprMayJunJulAugSepOctNovDec0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%May 1650%May 1650%Sep 2550%Sep 2550%Jun 290%Jun 290%Sep 490%Sep 490%Apr 3010%Apr 3010%Oct 1410%Oct 1410%0%Feb 220%Feb 22Jul 13100%Jul 13100%frigidfreezingvery coldcoldcool
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
The percentage of time spent in various temperature bands. The black line is the percentage chance that a given day is within the growing season.

Growing degree days are a measure of yearly heat accumulation used to predict plant and animal development, and defined as the integral of warmth above a base temperature, discarding any excess above a maximum temperature. In this report, we use a base of 50°F and a cap of 86°F.

Based on growing degree days alone, the first spring blooms in Tromsø should appear around July 3, only rarely appearing before June 17 or after July 24.

Growing Degree Days

Growing Degree Days in TromsøJanFebMarAprMayJunJulAugSepOctNovDec0°F50°F100°F150°F200°F250°F300°F350°F400°F450°FJul 390°FJul 390°FDec 31351°FDec 31351°F
The average growing degree days accumulated over the course of the year, with 25th to 75th and 10th to 90th percentile bands.

Solar Energy

This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.

The average daily incident shortwave solar energy experiences extreme seasonal variation over the course of the year.

The brighter period of the year lasts for 2.6 months, from May 12 to July 30, with an average daily incident shortwave energy per square meter above 4.2 kWh. The brightest day of the year is June 16, with an average of 5.3 kWh.

The darker period of the year lasts for 5.5 months, from September 30 to March 12, with an average daily incident shortwave energy per square meter below 1.1 kWh. The darkest day of the year is December 11, with an average of 0.0 kWh.

Average Daily Incident Shortwave Solar Energy

Average Daily Incident Shortwave Solar Energy in TromsøbrightdarkdarkJanFebMarAprMayJunJulAugSepOctNovDec0 kWh1 kWh2 kWh3 kWh4 kWh5 kWh6 kWh7 kWh8 kWhJun 165.3 kWhJun 165.3 kWhDec 110.0 kWhDec 110.0 kWhJul 304.2 kWhJul 304.2 kWhSep 301.1 kWhSep 301.1 kWhMar 121.1 kWhMar 121.1 kWh
The average daily shortwave solar energy reaching the ground per square meter (orange line), with 25th to 75th and 10th to 90th percentile bands.

Topography

For the purposes of this report, the geographical coordinates of Tromsø are 69.649 deg latitude, 18.955 deg longitude, and 36 ft elevation.

The topography within 2 miles of Tromsø contains large variations in elevation, with a maximum elevation change of 1,982 feet and an average elevation above sea level of 209 feet. Within 10 miles contains large variations in elevation (4,003 feet). Within 50 miles also contains extreme variations in elevation (5,981 feet).

The area within 2 miles of Tromsø is covered by trees (36%), artificial surfaces (36%), and water (17%), within 10 miles by trees (22%) and sparse vegetation (22%), and within 50 miles by water (43%) and trees (19%).

Data Sources

This report illustrates the typical weather in Tromsø, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.

Temperature and Dew Point

There are 4 weather stations near enough to contribute to our estimation of the temperature and dew point in Tromsø.

For each station, the records are corrected for the elevation difference between that station and Tromsø according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.

The estimated value at Tromsø is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Tromsø and a given station.

The stations contributing to this reconstruction are: Tromsø Airport, Langnes (97%, 4.0 kilometers, north); Bardufoss Airport (1.4%, 68 kilometers, south); Sørkjosen Airport (1.1%, 79 kilometers, east); and Andøya Andenes Airport (0.6%, 117 kilometers, west).

Other Data

All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Tables of the Sun, Moon and Planets , by Jean Meeus.

All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA's MERRA-2 Modern-Era Retrospective Analysis . This reanalysis combines a variety of wide-area measurements in a state-of-the-art global meteorological model to reconstruct the hourly history of weather throughout the world on a 50-kilometer grid.

Land Use data comes from the Global Land Cover SHARE database , published by the Food and Agriculture Organization of the United Nations.

Elevation data comes from the Shuttle Radar Topography Mission (SRTM) , published by NASA's Jet Propulsion Laboratory.

Names, locations, and time zones of places and some airports come from the GeoNames Geographical Database .

Time zones for aiports and weather stations are provided by AskGeo.com .

Maps are © Esri, with data from National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, and iPC.

Disclaimer

The information on this site is provided as is, without any assurances as to its accuracy or suitability for any purpose. Weather data is prone to errors, outages, and other defects. We assume no responsibility for any decisions made on the basis of the content presented on this site.

We draw particular cautious attention to our reliance on the MERRA-2 model-based reconstructions for a number of important data series. While having the tremendous advantages of temporal and spatial completeness, these reconstructions: (1) are based on computer models that may have model-based errors, (2) are coarsely sampled on a 50 km grid and are therefore unable to reconstruct the local variations of many microclimates, and (3) have particular difficulty with the weather in some coastal areas, especially small islands.

We further caution that our travel scores are only as good as the data that underpin them, that weather conditions at any given location and time are unpredictable and variable, and that the definition of the scores reflects a particular set of preferences that may not agree with those of any particular reader.