This report describes the typical weather at the Sangster International Airport (Montego Bay, Jamaica) weather station over the course of an average September. It is based on the historical records from 1974 to 2012. Earlier records are either unavailable or unreliable.
Montego Bay has a tropical monsoon climate with short dry season. The area within 25 mi of this station is covered by oceans and seas (55%) and forests (41%).
The month of September is characterized by essentially constant daily high temperatures, with daily highs around 88°F throughout the month, exceeding 91°F or dropping below 85°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 11:58 hours of daylight; the longest day is September 1 with 12:28 hours of daylight.
The earliest sunrise is at 5:57am on September 2; the latest sunset is at 6:26pm on September 1; the latest sunrise is at 6:02am on September 30; the earliest sunset is at 6:01pm on September 30.
Daylight saving time (DST) is not observed in 2012.
The median cloud cover is 49% (partly cloudy) and does not vary substantially over the course of the month.
On September 15, a representative day, the sky is clear or mostly clear 36% of the time, partly cloudy 23% of the time, and mostly cloudy or overcast 24% of the time.
The probability that precipitation will be observed at this location varies throughout the month. Precipitation is most likely around September 17, occurring in 60% of days. Precipitation is least likely around September 1, occurring in 55% of days.
Throughout September, the most common forms of precipitation are thunderstorms, moderate rain, and light rain.
Thunderstorms are the most severe precipitation observed during 75% of those days with precipitation. They are most likely around September 17, when it is observed during 45% of all days.
Moderate rain is the most severe precipitation observed during 14% of those days with precipitation. It is most likely around September 30, when it is observed during 10% of all days.
Light rain is the most severe precipitation observed during 11% of those days with precipitation. It is most likely around September 30, when it is observed during 7% 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 64% (mildly humid) to 91% (very humid) over the course of a typical September, rarely dropping below 57% (mildly humid) and reaching as high as 100% (very humid).
The air is driest around September 1, at which time the relative humidity drops below 69% (mildly humid) three days out of four; it is most humid around September 27, rising above 87% (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 71°F (very muggy) to 78°F (oppressive) and is rarely below 67°F (muggy) or above 81°F (very oppressive).
Over the course of September typical wind speeds vary from 0 mph to 18 mph (calm to moderate breeze), rarely exceeding 24 mph (strong breeze).
The highest average wind speed of 7 mph (light breeze) occurs around September 1, at which time the average daily maximum wind speed is 18 mph (moderate breeze).
The lowest average wind speed of 6 mph (light breeze) occurs around September 30, at which time the average daily maximum wind speed is 16 mph (moderate breeze).