This report describes the typical weather at the Boeing Field/King County International Airport (Seattle, Washington, United States) weather station over the course of an average February. It is based on the historical records from 1974 to 2012. Earlier records are either unavailable or unreliable.
Seattle, Washington has a mediterranean climate with dry warm summers and mild winters. The area within 25 mi of this station is covered by forests (61%), built-up areas (17%), oceans and seas (17%), and croplands (3%).
The month of February is characterized by gradually rising daily high temperatures, with daily highs around 50Â°F throughout the month, exceeding 59Â°F or dropping below 41Â°F only one day in ten.
Over the course of February, the length of the day is increasing. From the start to the end of the month, the length of the day increases by 1:30 hours, implying an average day-over-day increase of 3.1 minutes.
The shortest day of the month is February 1 with 9:34 hours of daylight; the longest day is February 29 with 11:04 hours of daylight.
The earliest sunrise is at 6:50am on February 29; the latest sunset is at 5:53pm on February 29; the latest sunrise is at 7:36am on February 1; the earliest sunset is at 5:10pm on February 1.
Daylight savings time is observed in 2012 but it neither starts nor ends in February, so the entire month is in standard time.
The median cloud cover is 97% (overcast) and does not vary substantially over the course of the month.
On February 15, a representative day, the sky is clear or mostly clear 17% of the time, partly cloudy 8% of the time, and mostly cloudy or overcast 75% of the time.
The average probability that some form of precipitation will be observed in a given day is 63%, with little variation over the course of the month.
Throughout February, the most common forms of precipitation are light rain and moderate rain.
Light rain is the most severe precipitation observed during 69% of those days with precipitation. It is most likely around February 29, when it is observed during 44% of all days.
Moderate rain is the most severe precipitation observed during 16% of those days with precipitation. It is most likely around February 2, when it is observed during 11% of all days.
The likelihood of snow falling is highest around February 1, occurring in 7% of days.
Either snow rarely accumulates at this location in February or snow depth measurements are unavailable or unreliable.
The relative humidity typically ranges from 56% (mildly humid) to 93% (very humid) over the course of a typical February, rarely dropping below 36% (comfortable) and reaching as high as 100% (very humid).
The air is driest around February 29, at which time the relative humidity drops below 66% (mildly humid) three days out of four; it is most humid around February 1, rising above 90% (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 February, the dew point typically varies from 31Â°F (dry) to 41Â°F (dry) and is rarely below 20Â°F (dry) or above 48Â°F (dry).
Over the course of February typical wind speeds vary from 0 mph to 13 mph (calm to moderate breeze), rarely exceeding 20 mph (fresh breeze).
The highest average wind speed of 7 mph (light breeze) occurs around February 22, at which time the average daily maximum wind speed is 13 mph (moderate breeze).
The lowest average wind speed of 7 mph (light breeze) occurs around February 1, at which time the average daily maximum wind speed is 12 mph (gentle breeze).