Average Weather For Castries, St. Lucia

Location

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 year. 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%).

Temperature

Over the course of a year, the temperature typically varies from 75°F to 88°F and is rarely below 73°F or above 89°F.

Daily High and Low Temperature

The daily average low (blue) and high (red) temperature with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile).

The warm season lasts from August 7 to October 13 with an average daily high temperature above 87°F. The hottest day of the year is September 4, with an average high of 88°F and low of 79°F.

The cold season lasts from December 19 to March 22 with an average daily high temperature below 84°F. The coldest day of the year is February 29, with an average low of 75°F and high of 83°F.

Fraction of Time Spent in Various Temperature Bands

The average fraction of time spent in various temperature bands: frigid (below 15°F), freezing (15°F to 32°F), cold (32°F to 50°F), cool (50°F to 65°F), comfortable (65°F to 75°F), warm (75°F to 85°F), hot (85°F to 100°F) and sweltering (above 100°F).

Sun

The length of the day varies significantly over the course of the year. The shortest day is December 21 with 11:18 hours of daylight; the longest day is June 20 with 12:58 hours of daylight.

Daily Hours of Daylight and Twilight

The number of hours during which the Sun is visible (black line), with various degrees of daylight, twilight, and night, indicated by the color bands. From bottom (most yellow) to top (most gray): full daylight, solar twilight (Sun is visible but less than 6° from the horizon), civil twilight (Sun is not visible but is less than 6° below the horizon), nautical twilight (Sun is between 6° and 12° below the horizon), astronomical twilight (Sun is between 12° and 18° below the horizon), and full night.

The earliest sunrise is at 5:35am on May 28 and the latest sunset is at 6:37pm on July 5. The latest sunrise is at 6:33am on January 23 and the earliest sunset is at 5:32pm on November 18.

Daylight saving time (DST) is not observed in 2012.

Daily Sunrise & Sunset with Twilight

The solar day over the course of the year 2012 . From bottom to top, the black lines are the previous solar midnight, sunrise, solar noon, sunset, and the next solar midnight. The day, twilights (solar, civil, nautical, and astronomical), and night are indicated by the color bands from yellow to gray.

Clouds

The median cloud cover ranges from 54% (partly cloudy) to 79% (partly cloudy). The sky is cloudiest on April 17 and clearest on December 7. The clearer part of the year begins around September 12. The cloudier part of the year begins around March 15.

Median Cloud Cover

The median daily cloud cover (black line) with percentile bands (inner band from 40th to 60th percentile, outer band from 25th to 75th percentile).

On December 7, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 37% of the time, and overcast or mostly cloudy 27% of the time.

On April 17, the cloudiest day of the year, the sky is overcast, mostly cloudy, or partly cloudy 50% of the time, and clear or mostly clear 7% of the time.

Cloud Cover Types

The fraction of time spent in each of the five sky cover categories. From top (most blue) to bottom (most gray), the categories are clear, mostly clear, partly cloudy, mostly cloudy, and overcast. Pink indicates missing data. Outside of the United States clear skies are often reported ambiguously, leading them to be lumped in with the missing data.

Precipitation

The probability that precipitation will be observed at this location varies throughout the year. Precipitation is most likely around July 30, occurring in 55% of days. Precipitation is least likely around February 21, occurring in 37% of days.

Probability of Precipitation at Some Point in the Day

The fraction of days in which various types of precipitation are observed. If more than one type of precipitation is reported in a given day, the more severe precipitation is counted. For example, if light rain is observed in the same day as a thunderstorm, that day counts towards the thunderstorm totals. The order of severity is from the top down in this graph, with the most severe at the bottom.

Over the entire year, the most common forms of precipitation are light rain, moderate rain, and thunderstorms.

Light rain is the most severe precipitation observed during 54% 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 33% of those days with precipitation. It is most likely around November 26, when it is observed during 19% of all days.

Thunderstorms are the most severe precipitation observed during 10% of those days with precipitation. They are most likely around August 29, when it is observed during 15% of all days.

Types of Precipitation Throughout the Year

Relative frequency of various types of precipitation over the course of a typical year.

During the warm season, which lasts from August 7 to October 13, there is a 50% average chance that precipitation will be observed at some point during a given day. When precipitation does occur it is most often in the form of light rain (48% of days with precipitation have at worst light rain), thunderstorms (26%), and moderate rain (26%).

During the cold season, which lasts from December 19 to March 22, there is a 41% average chance that precipitation will be observed at some point during a given day. When precipitation does occur it is most often in the form of light rain (61% of days with precipitation have at worst light rain) and moderate rain (37%).

Warm Season Precipitation

Cold Season Precipitation

Relative frequency of various types of precipitation during the warm and cold seasons respectively.

Snow

Either snow is exceptionally unlikely to fall at any time during the year at this location or this station does not reliably report precipitation types.

Humidity

The relative humidity typically ranges from 62% (mildly humid) to 94% (very humid) over the course of the year, rarely dropping below 56% (mildly humid) and reaching as high as 100% (very humid).

The air is driest around March 7, at which time the relative humidity drops below 65% (mildly humid) three days out of four; it is most humid around October 4, exceeding 91% (very humid) three days out of four.

Relative Humidity

The average daily high (blue) and low (brown) relative humidity with percentile bands (inner bands from 25th to 75th percentile, outer bands from 10th to 90th percentile).

Dew Point

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 year, the dew point typically varies from 68°F (muggy) to 78°F (oppressive) and is rarely below 65°F (mildy humid) or above 79°F (oppressive).

Dew Point

The daily average low (blue) and high (red) dew point with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile).

Wind

Over the course of the year typical wind speeds vary from 0 mph to 17 mph (calm to moderate breeze), rarely exceeding 76 mph (hurricane).

The highest average wind speed of 11 mph (gentle breeze) occurs around February 6, at which time the average daily maximum wind speed is 17 mph (moderate breeze).

The lowest average wind speed of 6 mph (light breeze) occurs around September 10, at which time the average daily maximum wind speed is 13 mph (moderate breeze).

Wind Speed

The average daily minimum (red), maximum (green), and average (black) wind speed with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile).
The wind is most often out of the east (35% of the time). The wind is least often out of the north west (0% of the time), south west (0% of the time), north (0% of the time), west (1% of the time), south (1% of the time), and north east (2% of the time).

Wind Directions Over the Entire Year

The fraction of time spent with the wind blowing from the various directions over the entire year. Values do not sum to 100% because the wind direction is undefined when the wind speed is zero.

Fraction of Time Spent with Various Wind Directions

The fraction of time spent with the wind blowing from the various directions on a daily basis. Stacked values do not always sum to 100% because the wind direction is undefined when the wind speed is zero.