This report describes the typical weather at the Cape Town International Airport (Cape Town, South Africa) weather station over the course of an average May. It is based on the historical records from 1994 to 2012. Earlier records are either unavailable or unreliable.
Cape Town has a mediterranean climate with dry warm summers and mild winters. The area within 25 mi of this station is covered by oceans and seas (40%), grasslands (33%), croplands (17%), built-up areas (6%), and forests (5%).
The month of May is characterized by gradually falling daily high temperatures, with daily highs ranging from 70°F to 66°F over the course of the month, exceeding 79°F or dropping below 60°F only one day in ten.
Over the course of May, the length of the day is gradually decreasing. The shortest day of the month is May 31 with 10:02 hours of daylight; the longest day is May 1 with 10:44 hours of daylight.
The earliest sunrise is at 7:21am on May 1; the latest sunset is at 6:05pm on May 1; the latest sunrise is at 7:42am on May 31; the earliest sunset is at 5:44pm on May 31.
Daylight savings time (DST) is not observed in 2012.
The median cloud cover ranges from 43% (partly cloudy) to 51% (partly cloudy). The trend is for the sky to be becoming cloudier with the median cloud cover increasing by 8% from the start to the end of the month.
On May 16, a representative day, the sky is clear or mostly clear 40% of the time, partly cloudy 12% of the time, and mostly cloudy or overcast 32% of the time.
The probability that precipitation will be observed at this location varies throughout the month. Precipitation is most likely around May 31, occurring in 42% of days. Precipitation is least likely around May 1, occurring in 32% of days.
Throughout May, the most common forms of precipitation are moderate rain and light rain.
Moderate rain is the most severe precipitation observed during 49% of those days with precipitation. It is most likely around May 31, when it is observed during 22% of all days.
Light rain is the most severe precipitation observed during 41% of those days with precipitation. It is most likely around May 28, when it is observed during 16% of all days.
Either snow is exceptionally unlikely to fall at this location in May or this station does not reliably report precipitation types.
The relative humidity typically ranges from 53% (mildly humid) to 96% (very humid) over the course of a typical May, rarely dropping below 32% (comfortable) and reaching as high as 100% (very humid).
The air is driest around May 1, at which time the relative humidity drops below 64% (mildly humid) three days out of four; it is most humid around May 25, rising above 94% (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 May, the dew point typically varies from 44°F (dry) to 57°F (comfortable) and is rarely below 37°F (dry) or above 60°F (comfortable).
The time of the month between May 1 and May 31 is the most comfortable, with dew points that are neither too dry nor too muggy.
Over the course of May typical wind speeds vary from 1 mph to 16 mph (light air to moderate breeze), rarely exceeding 24 mph (strong breeze).
The highest average wind speed of 9 mph (gentle breeze) occurs around May 1, at which time the average daily maximum wind speed is 16 mph (moderate breeze).
The lowest average wind speed of 9 mph (gentle breeze) occurs around May 23, at which time the average daily maximum wind speed is 14 mph (moderate breeze).