Average Weather In January For Reykjavík, Iceland

Location

This report describes the typical weather at the Reykjavík Airport (Reykjavík, Iceland) weather station over the course of an average January. It is based on the historical records from 1979 to 2012. Earlier records are either unavailable or unreliable.

Reykjavík has a humid subarctic continental climate with cool summers and no dry season. The area within 25 mi of this station is covered by oceans and seas (39%), shrublands (34%), forests (19%), and tundra (4%).

Temperature

The month of January is characterized by essentially constant daily high temperatures, with daily highs around 36°F throughout the month, exceeding 45°F or dropping below 27°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).
Daily low temperatures are around 28°F, falling below 17°F or exceeding 37°F only one day in ten.

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 2:32 hours, implying an average day-over-day increase of 4.9 minutes.

The shortest day of the month is January 2 with 4:24 hours of daylight; the longest day is January 31 with 6:56 hours of daylight.

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 10:13am on January 31; the latest sunset is at 5:09pm on January 31; the latest sunrise is at 11:19am on January 2; the earliest sunset is at 3:43pm on January 1.

Daylight savings time (DST) is not observed in 2012.

Daily Sunrise & Sunset with Twilight 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.

Clouds

The median cloud cover is 89% (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 18% of the time, partly cloudy 16% of the time, and mostly cloudy or overcast 58% 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 77%, 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, moderate rain, and light snow.

Moderate snow is the most severe precipitation observed during 52% of those days with precipitation. It is most likely around January 22, when it is observed during 41% of all days.

Moderate rain is the most severe precipitation observed during 23% of those days with precipitation. It is most likely around January 2, when it is observed during 18% of all days.

Light snow is the most severe precipitation observed during 12% of those days with precipitation. It is most likely around January 31, when it is observed during 10% 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 31, occurring in 52% 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 extremely unlikely. The chances of there being snow on the ground are highest around January 13, occurring 5% 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 27, with a median depth of 3.1"; the depth exceeds 3.7" 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 65% (mildly humid) to 90% (very humid) over the course of a typical January, rarely dropping below 51% (mildly humid) and reaching as high as 100% (very humid).

The air is driest around January 1, at which time the relative humidity drops below 73% (humid) three days out of four; it is most humid around January 23, rising above 86% (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 20°F (dry) to 31°F (dry) and is rarely below 7°F (dry) or above 42°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 4 mph to 26 mph (light breeze to strong breeze), rarely exceeding 41 mph (gale).

The highest average wind speed of 18 mph (fresh breeze) occurs around January 1, at which time the average daily maximum wind speed is 25 mph (strong breeze).

The lowest average wind speed of 15 mph (moderate breeze) occurs around January 10, at which time the average daily maximum wind speed is 25 mph (strong 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).
The wind is most often out of the east (24% of the time), south east (15% of the time), south (15% of the time), and north (12% of the time).

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.