This report describes the typical weather at the Penn Yan Airport (Penn Yan, New York, United States) weather station over the course of an average April. It is based on the historical records from 1999 to 2012. Earlier records are either unavailable or unreliable.
Penn Yan, New York has a humid continental climate with warm summers and no dry season. The area within 25 mi of this station is covered by forests (77%), grasslands (12%), lakes and rivers (8%), and croplands (2%).
The month of April is characterized by rapidly rising daily high temperatures, with daily highs increasing from 50°F to 63°F over the course of the month, exceeding 76°F or dropping below 36°F only one day in ten.
Over the course of April, the length of the day is increasing. From the start to the end of the month, the length of the day increases by 1:19 hours, implying an average day-over-day increase of 2.6 minutes.
The shortest day of the month is April 1 with 12:46 hours of daylight; the longest day is April 30 with 14:04 hours of daylight.
The earliest sunrise is at 6:03am on April 30; the latest sunset is at 8:08pm on April 30; the latest sunrise is at 6:49am on April 1; the earliest sunset is at 7:35pm 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 ranges from 39% (mostly clear) to 54% (partly cloudy). The trend is for the sky to be clearing with the median cloud cover decreasing by 14% from the start to the end of the month.
On April 30, the clearest day of the month, the sky is clear, mostly clear, or partly cloudy 56% of the time, and overcast or mostly cloudy 42% of the time.
On April 1, the cloudiest day of the month, the sky is overcast, mostly cloudy, or partly cloudy 49% of the time, and clear or mostly clear 44% of the time.
The average probability that some form of precipitation will be observed in a given day is 51%, with little variation over the course of the month.
Throughout April, the most common forms of precipitation are light rain, moderate rain, and light snow.
Light rain is the most severe precipitation observed during 34% of those days with precipitation. It is most likely around April 23, when it is observed during 20% of all days.
Moderate rain is the most severe precipitation observed during 20% of those days with precipitation. It is most likely around April 29, when it is observed during 11% of all days.
Light snow is the most severe precipitation observed during 20% of those days with precipitation. It is most likely around April 1, when it is observed during 15% of all days.
The likelihood of snow falling is highest around April 1, occurring in 22% of days.
Either snow rarely accumulates at this location in April or snow depth measurements are unavailable or unreliable.
The relative humidity typically ranges from 42% (comfortable) to 88% (very humid) over the course of a typical April, rarely dropping below 24% (dry) and reaching as high as 98% (very humid).
The air is driest around April 26, at which time the relative humidity drops below 52% (mildly humid) three days out of four; it is most humid around April 29, rising above 83% (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 24°F (dry) to 46°F (dry) and is rarely below 13°F (dry) or above 57°F (comfortable).
Over the course of April typical wind speeds vary from 0 mph to 15 mph (calm to moderate breeze), rarely exceeding 21 mph (fresh breeze).
The highest average wind speed of 8 mph (gentle breeze) occurs around April 4, at which time the average daily maximum wind speed is 15 mph (moderate breeze).
The lowest average wind speed of 7 mph (light breeze) occurs around April 28, at which time the average daily maximum wind speed is 14 mph (moderate breeze).