This report describes the typical weather at the Spartanburg Downtown Memorial Airport (Spartanburg, South Carolina, United States) weather station over the course of an average April. It is based on the historical records from 2009 to 2012. Earlier records are either unavailable or unreliable.
Spartanburg, South Carolina 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 (79%), croplands (17%), and built-up areas (4%).
The month of April is characterized by gradually rising daily high temperatures, with daily highs ranging from 73°F to 77°F over the course of the month, exceeding 83°F or dropping below 66°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 59 minutes, implying an average day-over-day increase of 2.0 minutes.
The shortest day of the month is April 1 with 12:36 hours of daylight; the longest day is April 30 with 13:35 hours of daylight.
The earliest sunrise is at 6:38am on April 30; the latest sunset is at 8:13pm on April 30; the latest sunrise is at 7:14am on April 1; the earliest sunset is at 7:50pm on April 1.
Daylight saving 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 29% (mostly clear) to 34% (mostly clear).
On April 15, a representative day, the sky is clear or mostly clear 48% of the time, partly cloudy 9% of the time, and mostly cloudy or overcast 28% of the time.
The probability that precipitation will be observed at this location varies throughout the month. Precipitation is most likely around April 29, occurring in 38% of days. Precipitation is least likely around April 2, occurring in 30% of days.
Throughout April, the most common forms of precipitation are thunderstorms, moderate rain, and light rain.
Thunderstorms are the most severe precipitation observed during 63% of those days with precipitation. They are most likely around April 17, when it is observed during 25% of all days.
Moderate rain is the most severe precipitation observed during 18% of those days with precipitation. It is most likely around April 7, when it is observed during 7% of all days.
Light rain is the most severe precipitation observed during 12% of those days with precipitation. It is most likely around April 29, 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 44% (comfortable) to 96% (very humid) over the course of a typical April, rarely dropping below 31% (comfortable) and reaching as high as 100% (very humid).
The air is driest around April 11, at which time the relative humidity drops below 51% (mildly humid) three days out of four; it is most humid around April 30, rising above 95% (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 43°F (dry) to 62°F (mildy humid) and is rarely below 36°F (dry) or above 69°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 0 mph to 13 mph (calm to moderate breeze), rarely exceeding 17 mph (moderate breeze).
The highest average wind speed of 6 mph (light breeze) occurs around April 14, at which time the average daily maximum wind speed is 13 mph (moderate breeze).
The lowest average wind speed of 5 mph (light breeze) occurs around April 30, at which time the average daily maximum wind speed is 11 mph (gentle breeze).