Climate and Average Weather Year Round in Saint Lucia St. Lucia
The climate in Saint Lucia is hot, oppressive, extremely windy, and mostly cloudy. Over the course of the year, the temperature typically varies from 76°F to 87°F and is rarely below 73°F or above 89°F.
Based on the beach/pool score, the best time of year to visit Saint Lucia for hot-weather activities is from mid December to early April.
Average Temperature in Saint Lucia
The temperature in Saint Lucia varies so little throughout the year that it is not entirely meaningful to discuss hot and cold seasons.
The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.
In Saint Lucia, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year.
The clearer part of the year in Saint Lucia begins around November 26 and lasts for 4.4 months, ending around April 6.
The clearest month of the year in Saint Lucia is January, during which on average the sky is clear, mostly clear, or partly cloudy 58% of the time.
The cloudier part of the year begins around April 6 and lasts for 7.6 months, ending around November 26.
The cloudiest month of the year in Saint Lucia is September, during which on average the sky is overcast or mostly cloudy 68% of the time.
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Saint Lucia varies throughout the year.
The wetter season lasts 6.3 months, from May 29 to December 7, with a greater than 30% chance of a given day being a wet day. The month with the most wet days in Saint Lucia is October, with an average of 13.0 days with at least 0.04 inches of precipitation.
The drier season lasts 5.7 months, from December 7 to May 29. The month with the fewest wet days in Saint Lucia is March, with an average of 5.3 days with at least 0.04 inches of precipitation.
Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. The month with the most days of rain alone in Saint Lucia is October, with an average of 13.0 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 44% on November 9.
To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. Saint Lucia experiences extreme seasonal variation in monthly rainfall.
Rain falls throughout the year in Saint Lucia. The month with the most rain in Saint Lucia is October, with an average rainfall of 5.7 inches.
The month with the least rain in Saint Lucia is February, with an average rainfall of 1.2 inches.
The length of the day in Saint Lucia varies over the course of the year. In 2023, the shortest day is December 21, with 11 hours, 19 minutes of daylight; the longest day is June 21, with 12 hours, 57 minutes of daylight.
The earliest sunrise is at 5:34 AM on June 1, and the latest sunrise is 57 minutes later at 6:31 AM on January 23. The earliest sunset is at 5:32 PM on November 20, and the latest sunset is 1 hour, 3 minutes later at 6:36 PM on July 9.
Daylight saving time (DST) is not observed in Saint Lucia during 2023.
The figure below presents a compact representation of the sun's elevation (the angle of the sun above the horizon) and azimuth (its compass bearing) for every hour of every day in the reporting period. The horizontal axis is the day of the year and the vertical axis is the hour of the day. For a given day and hour of that day, the background color indicates the azimuth of the sun at that moment. The black isolines are contours of constant solar elevation.
The figure below presents a compact representation of key lunar data for 2023. The horizontal axis is the day, the vertical axis is the hour of the day, and the colored areas indicate when the moon is above the horizon. The vertical gray bars (new Moons) and blue bars (full Moons) indicate key Moon phases.
We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.
The perceived humidity level in Saint Lucia, as measured by the percentage of time in which the humidity comfort level is muggy, oppressive, or miserable, does not vary significantly over the course of the year, staying within 1% of 99% throughout.
This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.
The average hourly wind speed in Saint Lucia experiences significant seasonal variation over the course of the year.
The windier part of the year lasts for 8.5 months, from November 25 to August 8, with average wind speeds of more than 15.3 miles per hour. The windiest month of the year in Saint Lucia is January, with an average hourly wind speed of 17.5 miles per hour.
The calmer time of year lasts for 3.5 months, from August 8 to November 25. The calmest month of the year in Saint Lucia is September, with an average hourly wind speed of 13.1 miles per hour.
The predominant average hourly wind direction in Saint Lucia is from the east throughout the year.
Saint Lucia is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.
The average water temperature experiences some seasonal variation over the course of the year.
The time of year with warmer water lasts for 3.0 months, from August 12 to November 12, with an average temperature above 83°F. The month of the year in Saint Lucia with the warmest water is September, with an average temperature of 84°F.
The time of year with cooler water lasts for 3.1 months, from January 10 to April 14, with an average temperature below 81°F. The month of the year in Saint Lucia with the coolest water is February, with an average temperature of 80°F.
Best Time of Year to Visit
To characterize how pleasant the weather is in Saint Lucia throughout the year, we compute two travel scores.
The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best time of year to visit Saint Lucia for general outdoor tourist activities is from early January to mid March, with a peak score in the first week of February.
Tourism Score in Saint Lucia
The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best time of year to visit Saint Lucia for hot-weather activities is from mid December to early April, with a peak score in the first week of February.
Beach/Pool Score in Saint Lucia
For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.
Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.
Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.
Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.
Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.
Definitions of the growing season vary throughout the world, but for the purposes of this report, we define it as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere).
Temperatures in Saint Lucia are sufficiently warm year round that it is not entirely meaningful to discuss the growing season in these terms. We nevertheless include the chart below as an illustration of the distribution of temperatures experienced throughout the year.
Growing degree days are a measure of yearly heat accumulation used to predict plant and animal development, and defined as the integral of warmth above a base temperature, discarding any excess above a maximum temperature. In this report, we use a base of 50°F and a cap of 86°F.
This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.
The average daily incident shortwave solar energy experiences some seasonal variation over the course of the year.
The brighter period of the year lasts for 2.5 months, from February 27 to May 11, with an average daily incident shortwave energy per square meter above 6.6 kWh. The brightest month of the year in Saint Lucia is April, with an average of 7.0 kWh.
The darker period of the year lasts for 2.7 months, from September 14 to December 5, with an average daily incident shortwave energy per square meter below 5.2 kWh. The darkest month of the year in Saint Lucia is October, with an average of 4.7 kWh.
For the purposes of this report, the geographical coordinates of Saint Lucia are 13.883 deg latitude, -60.967 deg longitude, and 0 ft elevation.
The topography within 2 miles of Saint Lucia is essentially flat, with a maximum elevation change of 0 feet and an average elevation above sea level of 0 feet. Within 10 miles is also essentially flat (0 feet). Within 50 miles is also essentially flat (0 feet).
The area within 2 miles of Saint Lucia is covered by trees (73%) and cropland (24%), within 10 miles by water (40%) and trees (39%), and within 50 miles by water (95%).
This report illustrates the typical weather in Saint Lucia, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.
The details of the data sources used for this report can be found on the Hewanorra International Airport page.
The information on this site is provided as is, without any assurances as to its accuracy or suitability for any purpose. Weather data is prone to errors, outages, and other defects. We assume no responsibility for any decisions made on the basis of the content presented on this site.
We draw particular cautious attention to our reliance on the MERRA-2 model-based reconstructions for a number of important data series. While having the tremendous advantages of temporal and spatial completeness, these reconstructions: (1) are based on computer models that may have model-based errors, (2) are coarsely sampled on a 50 km grid and are therefore unable to reconstruct the local variations of many microclimates, and (3) have particular difficulty with the weather in some coastal areas, especially small islands.
We further caution that our travel scores are only as good as the data that underpin them, that weather conditions at any given location and time are unpredictable and variable, and that the definition of the scores reflects a particular set of preferences that may not agree with those of any particular reader.
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