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Average Weather In January For Tromsø, Norway
Location
This report describes the typical weather at the Tromsø Airport (Tromsø, Norway) weather station over the course of an average January. 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
The month of January is characterized by essentially constant daily high temperatures, with daily highs around 30°F throughout the month, exceeding 40°F or dropping below 18°F only one day in ten.
Daily High and Low Temperature in January
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).
Fraction of Time Spent in Various Temperature Bands in January
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
Over the course of January, the length of the day is very rapidly increasing. From the start to the end of the month, the length of the day increases by 4:53 hours, implying an average day-over-day increase of 9.4 minutes.
The shortest day of the month is January 1 with 0:00 hours of daylight; the longest day is January 31 with 4:53 hours of daylight.
Due to its extreme latitude, Tromsø experiences polar night during winter. During this period of time, the Sun remains continuously below the horizon for a prolonged period of time.
January begins in polar night, which lasts until January 16.
Daily Hours of Daylight and Twilight in January
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.
The earliest sunrise is at 9:32am on January 31; the latest sunset is at 2:24pm on January 31; the latest sunrise is at 11:32am on January 16; the earliest sunset is at 12:17pm on January 16.
Daylight savings time is observed in 2012 but it neither starts nor ends in January, so the entire month is in standard time.
Daily Sunrise & Sunset with Twilight and Daylight Savings Time in January
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 81% (mostly cloudy) and does not vary substantially over the course of the month.
Median Cloud Cover in January
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 16, a representative day, the sky is clear or mostly clear 19% of the time, partly cloudy 20% of the time, and mostly cloudy or overcast 43% of the time.
Cloud Cover Types in January
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 average probability that some form of precipitation will be observed in a given day is 73%, with little variation over the course of the month.
Probability of Precipitation at Some Point in the Day in January
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.
Throughout January, the most common forms of precipitation are moderate snow and light snow.
Moderate snow is the most severe precipitation observed during 67% 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 20% of those days with precipitation. It is most likely around January 29, when it is observed during 15% of all days.
Types of Precipitation Throughout January
Relative frequency of various types of precipitation over the course of a typical January.
Snow
The likelihood of snow falling is highest around January 30, occurring in 66% of days.
Probability of Snow Fall Being Reported in a Given Day in January
Probability that snow will be reported at least once in a given day.
Accumulation at this location in January is very unlikely. The chances of there being snow on the ground are highest around January 29, occurring 6% of the time.
Chance of at Least Some Snow on the Ground in January
The probability that there is snow on the ground.
The snow is typically at its deepest on January 31, with a median depth of 13.1"; the depth exceeds 20.3" only one year out of ten.
Snow Depth When there is Snow on the Ground in January
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 64% (mildly humid) to 92% (very humid) over the course of a typical January, rarely dropping below 49% (comfortable) and reaching as high as 100% (very humid).
The air is driest around January 11, at which time the relative humidity drops below 73% (humid) three days out of four; it is most humid around January 17, rising above 90% (very humid) three days out of four.
Relative Humidity in January
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 typical January, the dew point typically varies from 13°F (dry) to 26°F (dry) and is rarely below 2°F (dry) or above 34°F (dry).
Dew Point in January
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 January typical wind speeds vary from 2 mph to 20 mph (light air to fresh breeze), rarely exceeding 31 mph (high wind).
The highest average wind speed of 12 mph (gentle breeze) occurs around January 24, at which time the average daily maximum wind speed is 20 mph (fresh breeze).
The lowest average wind speed of 11 mph (gentle breeze) occurs around January 3, at which time the average daily maximum wind speed is 19 mph (fresh breeze).
Wind Speed in January
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 in January
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 in January
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.