This report describes the typical weather at the Riga International Airport (Riga, Latvia) weather station over the course of an average January. It is based on the historical records from 1995 to 2012. Earlier records are either unavailable or unreliable.
Riga has a humid continental climate with warm summers and no dry season. The area within 25 mi of this station is covered by croplands (43%), oceans and seas (26%), forests (15%), grasslands (10%), and built-up areas (3%).
The month of January is characterized by essentially constant daily high temperatures, with daily highs around 31Â°F throughout the month, exceeding 41Â°F or dropping below 17Â°F only one day in ten.
Over the course of January, the length of the day is rapidly increasing. From the start to the end of the month, the length of the day increases by 1:33 hours, implying an average day-over-day increase of 3.0 minutes.
The shortest day of the month is January 1 with 6:51 hours of daylight; the longest day is January 31 with 8:23 hours of daylight.
The earliest sunrise is at 8:26am on January 31; the latest sunset is at 4:49pm on January 31; the latest sunrise is at 9:02am on January 1; the earliest sunset is at 3:53pm on January 1.
Daylight savings time is observed in 2012 but it neither starts nor ends in January, so the entire month is in standard time.
The median cloud cover is 100% (overcast) and does not vary substantially over the course of the month.
On January 16, a representative day, the sky is clear or mostly clear 2% of the time, partly cloudy 4% of the time, and mostly cloudy or overcast 79% of the time.
The average probability that some form of precipitation will be observed in a given day is 79%, with little variation over the course of the month.
Throughout January, the most common forms of precipitation are moderate snow, light snow, and light rain.
Moderate snow is the most severe precipitation observed during 42% of those days with precipitation. It is most likely around January 15, when it is observed during 34% of all days.
Light snow is the most severe precipitation observed during 33% of those days with precipitation. It is most likely around January 20, when it is observed during 27% of all days.
Light rain is the most severe precipitation observed during 15% of those days with precipitation. It is most likely around January 1, when it is observed during 14% of all days.
The likelihood of snow falling is highest around January 17, occurring in 64% of days.
Either snow rarely accumulates at this location in January or snow depth measurements are unavailable or unreliable.
The relative humidity typically ranges from 75% (humid) to 97% (very humid) over the course of a typical January, rarely dropping below 61% (mildly humid) and reaching as high as 100% (very humid).
The air is driest around January 31, at which time the relative humidity drops below 83% (humid) three days out of four; it is most humid around January 1, rising above 96% (very humid) three days out of four.
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 17Â°F (dry) to 30Â°F (dry) and is rarely below -1Â°F (dry) or above 39Â°F (dry).
Over the course of January typical wind speeds vary from 3 mph to 14 mph (light air to moderate breeze), rarely exceeding 21 mph (fresh breeze).
The highest average wind speed of 9 mph (gentle breeze) occurs around January 11, at which time the average daily maximum wind speed is 14 mph (moderate breeze).
The lowest average wind speed of 8 mph (gentle breeze) occurs around January 31, at which time the average daily maximum wind speed is 13 mph (moderate breeze).