This report describes the typical weather at the Erik Nielsen Whitehorse International Airport (Whitehorse, Yukon Territory, Canada) weather station over the course of an average April. It is based on the historical records from 1977 to 2012. Earlier records are either unavailable or unreliable.
Whitehorse, Yukon Territory has a humid subarctic continental climate with cool summers and no dry season. The area within 25 mi of this station is covered by forests (77%), tundra (19%), and lakes and rivers (2%).
The month of April is characterized by rapidly rising daily high temperatures, with daily highs increasing from 36°F to 50°F over the course of the month, exceeding 59°F or dropping below 28°F only one day in ten.
Over the course of April, 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 2:40 hours, implying an average day-over-day increase of 5.3 minutes.
The shortest day of the month is April 1 with 13:26 hours of daylight; the longest day is April 30 with 16:06 hours of daylight.
The earliest sunrise is at 5:55am on April 30; the latest sunset is at 10:01pm on April 30; the latest sunrise is at 7:22am on April 1; the earliest sunset is at 8:47pm on April 1.
Daylight savings time is observed in 2012 but it neither starts nor ends in April, so the entire month is in daylight time.
The median cloud cover is 80% (partly cloudy) and does not vary substantially over the course of the month.
On April 15, a representative day, the sky is clear or mostly clear 31% of the time, partly cloudy 10% of the time, and mostly cloudy or overcast 56% of the time.
The average probability that some form of precipitation will be observed in a given day is 38%, with little variation over the course of the month.
Throughout April, the most common forms of precipitation are light snow, light rain, and moderate snow.
Light snow is the most severe precipitation observed during 64% of those days with precipitation. It is most likely around April 1, when it is observed during 31% of all days.
Light rain is the most severe precipitation observed during 20% of those days with precipitation. It is most likely around April 30, when it is observed during 14% of all days.
Moderate snow is the most severe precipitation observed during 11% of those days with precipitation. It is most likely around April 1, when it is observed during 5% of all days.
The likelihood of snow falling is highest around April 1, occurring in 36% of days.
Accumulation at this location in April is about as likely as not. The chances of there being snow on the ground are highest around April 1, occurring 52% of the time.
The snow is typically at its deepest on April 1, with a median depth of 10.3"; the depth exceeds 15.0" only one year out of ten.
The relative humidity typically ranges from 33% (comfortable) to 79% (humid) over the course of a typical April, rarely dropping below 23% (dry), or exceeding 94% (very humid).
The air is driest around April 30, at which time the relative humidity drops below 38% (comfortable) three days out of four; it is most humid around April 1, rising above 71% (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 April, the dew point typically varies from 8°F (dry) to 28°F (dry) and is rarely below -5°F (dry) or above 35°F (dry).
Over the course of April typical wind speeds vary from 0 mph to 15 mph (calm to moderate breeze), rarely exceeding 22 mph (fresh breeze).
The highest average wind speed of 8 mph (gentle breeze) occurs around April 6, at which time the average daily maximum wind speed is 15 mph (moderate breeze).
The lowest average wind speed of 8 mph (gentle breeze) occurs around April 29, at which time the average daily maximum wind speed is 15 mph (moderate breeze).