This report describes the typical weather at the Keesler Air Force Base (Biloxi, Mississippi, 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.
Biloxi, Mississippi has a warm humid temperate climate with hot summers and no dry season. The area within 25 mi of this station is covered by forests (49%), oceans and seas (40%), and croplands (10%).
The month of April is characterized by rising daily high temperatures, with daily highs increasing from 72°F to 79°F over the course of the month, exceeding 84°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 6:13am on April 30; the latest sunset is at 7:34pm on April 30; the latest sunrise is at 6:44am on April 1; the earliest sunset is at 7:15pm 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 60% (partly cloudy) to 66% (partly cloudy). The trend is for the sky to be clearing with the median cloud cover decreasing by 6% from the start to the end of the month.
On April 15, a representative day, the sky is clear or mostly clear 34% of the time, partly cloudy 17% of the time, and mostly cloudy or overcast 47% of the time.
The average probability that some form of precipitation will be observed in a given day is 35%, with little variation over the course of the month.
Throughout April, the most common forms of precipitation are thunderstorms and light rain.
Thunderstorms are the most severe precipitation observed during 53% of those days with precipitation. They are most likely around April 30, when it is observed during 21% of all days.
Light rain is the most severe precipitation observed during 34% of those days with precipitation. It is most likely around April 1, when it is observed during 14% 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 55% (mildly humid) to 92% (very humid) over the course of a typical April, rarely dropping below 29% (dry) and reaching as high as 100% (very humid).
The air is driest around April 15, at which time the relative humidity drops below 70% (mildly humid) three days out of four; it is most humid around April 4, rising above 88% (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 April, the dew point typically varies from 50°F (dry) to 68°F (muggy) and is rarely below 33°F (dry) or above 75°F (very muggy).
Over the course of April typical wind speeds vary from 1 mph to 14 mph (light air to moderate breeze), rarely exceeding 19 mph (fresh breeze).
The highest average wind speed of 8 mph (gentle breeze) occurs around April 5, at which time the average daily maximum wind speed is 14 mph (moderate breeze).
The lowest average wind speed of 8 mph (light breeze) occurs around April 26, at which time the average daily maximum wind speed is 13 mph (moderate breeze).