This report describes the typical weather at the Mayport Naval Station (Jacksonville, Florida, United States) weather station over the course of an average April. It is based on the historical records from 1974 to 2012. Earlier records are either unavailable or unreliable.
Jacksonville, Florida has a warm humid temperate climate with hot summers and no dry season. The area within 25 mi of this station is covered by oceans and seas (47%), forests (21%), croplands (17%), built-up areas (7%), and lakes and rivers (5%).
The month of April is characterized by rising daily high temperatures, with daily highs increasing from 74°F to 80°F over the course of the month, exceeding 88°F or dropping below 65°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 50 minutes, implying an average day-over-day increase of 1.7 minutes.
The shortest day of the month is April 1 with 12:31 hours of daylight; the longest day is April 30 with 13:21 hours of daylight.
The earliest sunrise is at 6:43am on April 30; the latest sunset is at 8:04pm on April 30; the latest sunrise is at 7:14am on April 1; the earliest sunset is at 7:45pm 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 46% (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 38% of the time, partly cloudy 18% of the time, and mostly cloudy or overcast 29% of the time.
The average probability that some form of precipitation will be observed in a given day is 27%, with little variation over the course of the month.
Throughout April, the most common forms of precipitation are thunderstorms, light rain, and moderate rain.
Thunderstorms are the most severe precipitation observed during 41% of those days with precipitation. They are most likely around April 29, when it is observed during 13% of all days.
Light rain is the most severe precipitation observed during 38% of those days with precipitation. It is most likely around April 8, when it is observed during 11% of all days.
Moderate rain is the most severe precipitation observed during 16% of those days with precipitation. It is most likely around April 1, when it is observed during 5% 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 50% (comfortable) to 88% (very humid) over the course of a typical April, rarely dropping below 30% (dry) and reaching as high as 100% (very humid).
The air is driest around April 26, at which time the relative humidity drops below 59% (mildly humid) three days out of four; it is most humid around April 3, rising above 81% (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 48°F (dry) to 64°F (mildy humid) and is rarely below 35°F (dry) or above 71°F (muggy).
The time of the month between April 1 and April 30 is the most comfortable, with dew points that are neither too dry nor too muggy.
Over the course of April typical wind speeds vary from 1 mph to 14 mph (light air to moderate breeze), rarely exceeding 20 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 14 mph (moderate breeze).
The lowest average wind speed of 8 mph (gentle breeze) occurs around April 1, at which time the average daily maximum wind speed is 14 mph (moderate breeze).