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.
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 12 to April 1, 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 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
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 16 and lasts for 5.4 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 6.6 months, ending around April 16. 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.
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
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
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 7.4 months, from September 30 to May 11, 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 11 to September 30. The least snow falls around July 31, with an average total liquid-equivalent accumulation of 0.0 inches.
Average Liquid-Equivalent Monthly Snowfall
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 2017, the Sun is continuously above the horizon for 2.3 months, rising at 1:13 AM on May 17, and not setting again until 12:33 AM on July 26.
In the winter in Tromsø during 2017, the Sun is continuously below the horizon for 1.6 months, setting at 12:01 PM on November 26, and not rising again until 11:26 AM on January 15.
Hours of Daylight and Twilight
Daylight saving time (DST) is observed in Tromsø during 2017, starting in the spring on March 26, lasting 7.1 months, and ending in the fall on October 29.
Sunrise & Sunset with Twilight and Daylight Saving Time
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
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 22 to April 26, with average wind speeds of more than 4.4 miles per hour. The windiest day of the year is January 30, with an average hourly wind speed of 6.0 miles per hour.
The calmer time of year lasts for 5.9 months, from April 26 to October 22. The calmest day of the year is August 1, with an average hourly wind speed of 2.8 miles per hour.
Average Wind Speed
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.
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 2.5 months, from July 8 to September 22, 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 13, 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
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 11 to July 31, 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 29 to March 13, 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
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%).
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).
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.