This report describes the typical weather at the Phoenix Deer Valley Airport (Phoenix, Arizona, United States) weather station over the course of an average April. It is based on the historical records from 1997 to 2012. Earlier records are either unavailable or unreliable.
Phoenix, Arizona has a hot desert climate. The area within 25 mi of this station is covered by shrublands (86%), grasslands (8%), built-up areas (3%), and croplands (2%).
The month of April is characterized by rapidly rising daily high temperatures, with daily highs increasing from 77°F to 86°F over the course of the month, exceeding 95°F or dropping below 67°F only one day in ten.
Over the course of April, the length of the day is gradually increasing. From the start to the end of the month, the length of the day increases by 57 minutes, implying an average day-over-day increase of 1.9 minutes.
The shortest day of the month is April 1 with 12:34 hours of daylight; the longest day is April 30 with 13:31 hours of daylight.
The earliest sunrise is at 5:40am on April 30; the latest sunset is at 7:12pm on April 30; the latest sunrise is at 6:15am on April 1; the earliest sunset is at 6:49pm on April 1.
Daylight savings time (DST) is not observed in 2012.
The median cloud cover is 0% (clear) and does not vary substantially over the course of the month.
On April 15, a representative day, the sky is clear or mostly clear 84% of the time, partly cloudy 3% of the time, and mostly cloudy or overcast 8% of the time.
The average probability that some form of precipitation will be observed in a given day is 9%, with little variation over the course of the month.
Throughout April, the most common forms of precipitation are light rain, moderate rain, and thunderstorms.
Light rain is the most severe precipitation observed during 41% of those days with precipitation. It is most likely around April 1, when it is observed during 5% of all days.
Moderate rain is the most severe precipitation observed during 26% of those days with precipitation. It is most likely around April 1, when it is observed during 3% of all days.
Thunderstorms are the most severe precipitation observed during 24% of those days with precipitation. They are most likely around April 1, when it is observed during 3% of all days.
Either snow is exceptionally unlikely to fall at this location in April or this station does not reliably report precipitation types.
The relative humidity typically ranges from 12% (very dry) to 50% (comfortable) over the course of a typical April, rarely dropping below 6% (very dry), or exceeding 80% (humid).
The air is driest around April 30, at which time the relative humidity drops below 16% (dry) three days out of four; it is most humid around April 1, rising above 34% (comfortable) 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 21°F (dry) to 36°F (dry) and is rarely below 9°F (dry) or above 47°F (dry).
Over the course of April typical wind speeds vary from 0 mph to 15 mph (calm to moderate breeze), rarely exceeding 25 mph (strong breeze).
The highest average wind speed of 8 mph (gentle breeze) occurs around April 19, 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 1, at which time the average daily maximum wind speed is 14 mph (moderate breeze).