This report describes the typical weather at the George F. L. Charles Airport (Vigie Airport) (Castries, St. Lucia) weather station over the course of an average August. It is based on the historical records from 2008 to 2012. Earlier records are either unavailable or unreliable.
Castries has a tropical savanna climate with dry winters. The area within 25 mi of this station is covered by oceans and seas (88%), grasslands (10%), and croplands (3%).
The month of August is characterized by essentially constant daily high temperatures, with daily highs around 87°F throughout the month, exceeding 89°F or dropping below 86°F only one day in ten.
Over the course of August, the length of the day is essentially constant. The shortest day of the month is August 31 with 12:24 hours of daylight; the longest day is August 1 with 12:44 hours of daylight.
The earliest sunrise is at 5:48am on August 1; the latest sunset is at 6:32pm on August 1; the latest sunrise is at 5:52am on August 31; the earliest sunset is at 6:16pm on August 31.
Daylight saving time (DST) is not observed in 2012.
The median cloud cover is 71% (partly cloudy) and does not vary substantially over the course of the month.
On August 16, a representative day, the sky is clear or mostly clear 13% of the time, partly cloudy 19% of the time, and mostly cloudy or overcast 30% of the time.
The probability that precipitation will be observed at this location varies throughout the month. Precipitation is most likely around August 2, occurring in 55% of days. Precipitation is least likely around August 26, occurring in 50% of days.
Throughout August, the most common forms of precipitation are light rain, moderate rain, and thunderstorms.
Light rain is the most severe precipitation observed during 50% of those days with precipitation. It is most likely around August 2, when it is observed during 30% of all days.
Moderate rain is the most severe precipitation observed during 25% of those days with precipitation. It is most likely around August 4, when it is observed during 14% of all days.
Thunderstorms are the most severe precipitation observed during 24% of those days with precipitation. They are most likely around August 29, when it is observed during 15% of all days.
Either snow is exceptionally unlikely to fall at this location in August or this station does not reliably report precipitation types.
The relative humidity typically ranges from 66% (mildly humid) to 93% (very humid) over the course of a typical August, rarely dropping below 62% (mildly humid) and reaching as high as 99% (very humid).
The air is driest around August 28, at which time the relative humidity drops below 68% (mildly humid) three days out of four; it is most humid around August 8, rising above 90% (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 August, the dew point typically varies from 74°F (very muggy) to 78°F (oppressive) and is rarely below 72°F (very muggy) or above 79°F (oppressive).
Over the course of August typical wind speeds vary from 1 mph to 14 mph (calm to moderate breeze), rarely exceeding 76 mph (hurricane).
The highest average wind speed of 9 mph (gentle breeze) occurs around August 1, at which time the average daily maximum wind speed is 14 mph (moderate breeze).
The lowest average wind speed of 7 mph (light breeze) occurs around August 10, at which time the average daily maximum wind speed is 13 mph (moderate breeze).