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 January. 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 January is characterized by essentially constant daily high temperatures, with daily highs around 83°F throughout the month, exceeding 85°F or dropping below 81°F only one day in ten.
Over the course of January, the length of the day is essentially constant. The shortest day of the month is January 4 with 11:19 hours of daylight; the longest day is January 31 with 11:32 hours of daylight.
The earliest sunrise is at 6:28am on January 1; the latest sunset is at 6:03pm on January 31; the latest sunrise is at 6:33am on January 23; the earliest sunset is at 5:47pm on January 1.
Daylight saving time (DST) is not observed in 2012.
The median cloud cover is 55% (partly cloudy) and does not vary substantially over the course of the month.
On January 16, a representative day, the sky is clear or mostly clear 18% of the time, partly cloudy 21% of the time, and mostly cloudy or overcast 25% of the time.
The average probability that some form of precipitation will be observed in a given day is 42%, with little variation over the course of the month.
Throughout January, the most common forms of precipitation are light rain and moderate rain.
Light rain is the most severe precipitation observed during 61% of those days with precipitation. It is most likely around January 27, when it is observed during 27% of all days.
Moderate rain is the most severe precipitation observed during 36% of those days with precipitation. It is most likely around January 17, when it is observed during 17% of all days.
Either snow is exceptionally unlikely to fall at this location in January or this station does not reliably report precipitation types.
The relative humidity typically ranges from 63% (mildly humid) to 90% (very humid) over the course of a typical January, rarely dropping below 56% (mildly humid) and reaching as high as 98% (very humid).
The air is driest around January 31, at which time the relative humidity drops below 66% (mildly humid) three days out of four; it is most humid around January 1, rising above 85% (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 January, the dew point typically varies from 68°F (muggy) to 74°F (very muggy) and is rarely below 66°F (muggy) or above 76°F (very muggy).
Over the course of January typical wind speeds vary from 5 mph to 17 mph (light breeze to moderate breeze), rarely exceeding 23 mph (fresh breeze).
The highest average wind speed of 11 mph (gentle breeze) occurs around January 31, at which time the average daily maximum wind speed is 17 mph (moderate breeze).
The lowest average wind speed of 9 mph (gentle breeze) occurs around January 1, at which time the average daily maximum wind speed is 15 mph (moderate breeze).