Average Weather For Tromsø, Norway
Location
This report describes the typical weather at the Tromsø Airport (Tromsø, Norway) weather station over the course of an average year. It is based on the historical records from 1974 to 2012. Earlier records are either unavailable or unreliable.
Tromsø has a humid subarctic continental climate with cool summers and no dry season. The area within 25 mi of this station is covered by tundra (47%), oceans and seas (36%), and forests (14%).
Temperature
Over the course of a year, the temperature typically varies from 20°F to 60°F and is rarely below 9°F or above 69°F.
Daily High and Low Temperature
The daily average low (blue) and high (red) temperature with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile).
The warm season lasts from June 14 to September 3 with an average daily high temperature above 53°F. The hottest day of the year is July 25, with an average high of 60°F and low of 49°F.
The cold season lasts from November 16 to March 31 with an average daily high temperature below 35°F. The coldest day of the year is February 1, with an average low of 20°F and high of 28°F.
Fraction of Time Spent in Various Temperature Bands
The average fraction of time spent in various temperature bands: frigid (below 15°F), freezing (15°F to 32°F), cold (32°F to 50°F), cool (50°F to 65°F), comfortable (65°F to 75°F), warm (75°F to 85°F), hot (85°F to 100°F) and sweltering (above 100°F).
Sun
The length of the day varies significantly over the course of the year. The shortest day is December 21 with 0:00 hours of daylight; the longest day is June 20 with 24:00 hours of daylight.
Due to its extreme latitude, Tromsø experiences polar day (also known as the midnight Sun) during summer and polar night during winter. 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 summer, the Sun is continuously above the horizon for 67 days, from May 18 to July 24.
In winter, the Sun is continuously below the horizon for 49 days, from November 27 to January 15.
Daily Hours of Daylight and Twilight
The number of hours during which the Sun is visible (black line), with various degrees of daylight, twilight, and night, indicated by the color bands. From bottom (most yellow) to top (most gray): full daylight, solar twilight (Sun is visible but less than 6° from the horizon), civil twilight (Sun is not visible but is less than 6° below the horizon), nautical twilight (Sun is between 6° and 12° below the horizon), astronomical twilight (Sun is between 12° and 18° below the horizon), and full night.
Daylight savings time (DST) is observed in this location during 2012, starting in the spring on March 25 and ending in the fall on October 28.
Daily Sunrise & Sunset with Twilight and Daylight Savings Time
The solar day over the course of the year 2012 . From bottom to top, the black lines are the previous solar midnight, sunrise, solar noon, sunset, and the next solar midnight. The day, twilights (solar, civil, nautical, and astronomical), and night are indicated by the color bands from yellow to gray. The transitions to and from daylight savings time are indicated by the "DST" labels.
Clouds
The median cloud cover is 85% (mostly cloudy) and does not vary substantially over the course of the year.
Median Cloud Cover
The median daily cloud cover (black line) with percentile bands (inner band from 40th to 60th percentile, outer band from 25th to 75th percentile).
On January 6, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 40% of the time, and overcast or mostly cloudy 43% of the time.
On September 26, the cloudiest day of the year, the sky is overcast, mostly cloudy, or partly cloudy 77% of the time, and clear or mostly clear 16% of the time.
Cloud Cover Types
The fraction of time spent in each of the five sky cover categories. From top (most blue) to bottom (most gray), the categories are clear, mostly clear, partly cloudy, mostly cloudy, and overcast. Pink indicates missing data. Outside of the United States clear skies are often reported ambiguously, leading them to be lumped in with the missing data.
Precipitation
The probability that precipitation will be observed at this location varies throughout the year. Precipitation is most likely around September 30, occurring in 77% of days. Precipitation is least likely around July 24, occurring in 64% of days.
Probability of Precipitation at Some Point in the Day
The fraction of days in which various types of precipitation are observed. If more than one type of precipitation is reported in a given day, the more severe precipitation is counted. For example, if light rain is observed in the same day as a thunderstorm, that day counts towards the thunderstorm totals. The order of severity is from the top down in this graph, with the most severe at the bottom.
Over the entire year, the most common forms of precipitation are moderate rain, moderate snow, light snow, and light rain.
Moderate rain is the most severe precipitation observed during 36% of those days with precipitation. It is most likely around September 15, when it is observed during 49% of all days.
Moderate snow is the most severe precipitation observed during 36% of those days with precipitation. It is most likely around January 17, when it is observed during 50% of all days.
Light snow is the most severe precipitation observed during 13% of those days with precipitation. It is most likely around February 7, when it is observed during 15% of all days.
Light rain is the most severe precipitation observed during 12% of those days with precipitation. It is most likely around August 9, when it is observed during 15% of all days.
Types of Precipitation Throughout the Year
Relative frequency of various types of precipitation over the course of a typical year.
During the warm season, which lasts from June 14 to September 3, there is a 66% average chance that precipitation will be observed at some point during a given day. When precipitation does occur it is most often in the form of moderate rain (69% of days with precipitation have at worst moderate rain), light rain (21%), and drizzle (6%).
During the cold season, which lasts from November 16 to March 31, there is a 72% average chance that precipitation will be observed at some point during a given day. When precipitation does occur it is most often in the form of moderate snow (64% of days with precipitation have at worst moderate snow), light snow (19%), and moderate rain (10%).
Warm Season Precipitation
Cold Season Precipitation
Relative frequency of various types of precipitation during the warm and cold seasons respectively.
Snow
The likelihood of snow falling is highest around February 6, occurring in 66% of days. The season in which it is relatively likely for snow to fall spans from October 7 to May 18.
Probability of Snow Fall Being Reported in a Given Day
Probability that snow will be reported at least once in a given day. The season is defined as the period during which the probability is greater than one third the maximum probability.
During peak snow season, accumulation at this location on a given day is very unlikely. The chances of there being snow on the ground are highest around February 6, occurring 7% of the time.
Chance of at Least Some Snow on the Ground
The probability that there is snow on the ground. The season is defined as the period during which the probability is greater than one third of the maximum probability.
The snow is typically at its deepest on February 16, with a median depth of 19.8"; the depth exceeds 28.7" only one year out of ten.
Snow Depth When there is Snow on the Ground
The median depth of snow during times when there is at least some snow on the ground, with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile).
Humidity
The relative humidity typically ranges from 55% (mildly humid) to 94% (very humid) over the course of the year, rarely dropping below 38% (comfortable) and reaching as high as 100% (very humid).
The air is driest around May 17, at which time the relative humidity drops below 64% (mildly humid) three days out of four; it is most humid around September 9, exceeding 92% (very humid) three days out of four.
Relative Humidity
The average daily high (blue) and low (brown) relative humidity with percentile bands (inner bands from 25th to 75th percentile, outer bands from 10th to 90th percentile).
Dew Point
Dew point is often a better measure of how comfortable a person will find the weather than relative humidity because it more directly relates to whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid.
Over the course of a year, the dew point typically varies from 13°F (dry) to 50°F (very comfortable) and is rarely below 2°F (dry) or above 56°F (comfortable).
Dew Point
The daily average low (blue) and high (red) dew point with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile).
Wind
Over the course of the year typical wind speeds vary from 0 mph to 21 mph (calm to fresh breeze), rarely exceeding 31 mph (high wind).
The highest average wind speed of 12 mph (moderate breeze) occurs around February 16, at which time the average daily maximum wind speed is 21 mph (fresh breeze).
The lowest average wind speed of 6 mph (light breeze) occurs around August 7, at which time the average daily maximum wind speed is 13 mph (moderate breeze).
Wind Speed
The average daily minimum (red), maximum (green), and average (black) wind speed with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile).
Wind Directions Over the Entire Year
The fraction of time spent with the wind blowing from the various directions over the entire year. Values do not sum to 100% because the wind direction is undefined when the wind speed is zero.
Fraction of Time Spent with Various Wind Directions
The fraction of time spent with the wind blowing from the various directions on a daily basis. Stacked values do not always sum to 100% because the wind direction is undefined when the wind speed is zero.