This report describes the typical weather at the Banjul International Airport (Banjul, The Gambia) weather station over the course of an average September. It is based on the historical records from 2007 to 2012. Earlier records are either unavailable or unreliable.
Banjul has a tropical savanna climate with dry winters. The area within 25 mi of this station is covered by oceans and seas (69%) and croplands (27%).
The month of September is characterized by gradually rising daily high temperatures, with daily highs around 88°F throughout the month, exceeding 92°F or dropping below 84°F only one day in ten.
Over the course of September, the length of the day is essentially constant. The shortest day of the month is September 30 with 12:01 hours of daylight; the longest day is September 1 with 12:22 hours of daylight.
The earliest sunrise is at 6:56am on September 2; the latest sunset is at 7:18pm on September 1; the latest sunrise is at 6:57am on September 29; the earliest sunset is at 6:58pm on September 30.
Daylight saving time (DST) is not observed in 2012.
The median cloud cover ranges from 68% (partly cloudy) to 78% (partly cloudy). The trend is for the sky to be clearing with the median cloud cover decreasing by 10% from the start to the end of the month.
On September 30, the clearest day of the month, the sky is clear, mostly clear, or partly cloudy 32% of the time, and overcast or mostly cloudy 32% of the time.
On September 1, the cloudiest day of the month, the sky is overcast, mostly cloudy, or partly cloudy 82% of the time, and clear or mostly clear 2% of the time.
The probability that precipitation will be observed at this location varies throughout the month. Precipitation is most likely around September 1, occurring in 71% of days. Precipitation is least likely around September 30, occurring in 47% of days.
Throughout September, the most common forms of precipitation are thunderstorms and light rain.
Thunderstorms are the most severe precipitation observed during 84% of those days with precipitation. They are most likely around September 1, when it is observed during 60% of all days.
Light rain is the most severe precipitation observed during 12% of those days with precipitation. It is most likely around September 1, when it is observed during 9% of all days.
Either snow is exceptionally unlikely to fall at this location in September or this station does not reliably report precipitation types.
The relative humidity typically ranges from 65% (mildly humid) to 99% (very humid) over the course of a typical September, rarely dropping below 58% (mildly humid) and reaching as high as 100% (very humid).
The air is driest around September 30, at which time the relative humidity drops below 68% (mildly humid) three days out of four; it is most humid around September 4, rising above 99% (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 September, the dew point typically varies from 72°F (very muggy) to 80°F (oppressive) and is rarely below 69°F (muggy) or above 82°F (very oppressive).
Over the course of September typical wind speeds vary from 0 mph to 13 mph (calm to moderate breeze), rarely exceeding 23 mph (fresh breeze).
The highest average wind speed of 4 mph (light breeze) occurs around September 1, at which time the average daily maximum wind speed is 13 mph (moderate breeze).
The lowest average wind speed of 3 mph (light air) occurs around September 16, at which time the average daily maximum wind speed is 12 mph (moderate breeze).