General Overview

Occupying a position at the Lesser Antilles, Saint Lucia is an island belonging to the Commonwealth with a tropical climate. This means that it is hot throughout the year, with two distinct seasons – a dry and relatively cool season starting in late December and ending in May, and a humid, rainy, and hot season from mid-June through early December.

As for the average annual temperature in Saint Lucia, it does not offer dramatic changes. This is expected from an island located in the Deep Caribbean, or the Southern Caribbean, though. So, the average annual temperatures stay more or less within the same comfortable and warm range of around 27.3oC (81oF).

As you can see in the table below, the capital of the country, Castries, experiences very little variation between the warmest and coolest period, as it sits off the northwestern coast of Saint Lucia. The further up the mountains we move, though, the chillier and more dramatic the temperature changes are.

Average temperatures in Celsius (Castries)

Average temperatures in Fahrenheit (Castries)

Where the island startles weather-wise compared to the other Caribbean islands is in the number of rainy days per month. Unlike other of its siblings, it has an unusually high number of rainy days each month, taking over almost half of each month for the most part of the year. The good part of it all, though, is that the rains are usually short-lived and often fall in the afternoon, leaving visitors with plenty of time to enjoy their outdoor ventures. Plus, these rains are responsible for the profound natural beauty and lush scenery that distinguishes Saint Lucia.

What to Expect From Saint Lucia’s Dry & Wet Seasons

The dry season is also the high season in Saint Lucia and is characterised by cooler temperatures, lower humidity, and less chance of rain. The driest month is March. As for the rainy or wet season, it is also hurricane season (from September through October). This means lots of rainfalls that are usually heavy, but quick, with the coastal regions experiencing significantly less rainfall than the rainforests. On the flip side, although humidity is higher, especially during the months of July and August, the temperatures are higher by a couple of degrees. As for the wettest month, that would be October.

Hurricane Season 

Saint Lucia can be affected by a hurricane between June through November. However, despite being located in the heart of the Caribbean area which aggravates and produces massive tropical storm cells, hurricanes usually hit the northwest part of Saint Lucia. In any case, Saint Lucia is certainly vulnerable to tropical storms and cyclones.

Rainfall 

The location and the altitude play a crucial role in the rainfall. As explained above, the coastal areas receive less rainfall than the inland elevations, while the regions situated the closest to the mountains receive much larger amounts of rain than their more remote counterparts.

For example, a south coast city, such as Vieux Fort, which also sits in the driest point of Saint Lucia’s south shore, receives around 1,400 millimetres of rain annually (around 55 inches). At the same time, Castries, among other coastal areas, receives around 2,000 millimetres of rain annually (about 79 inches). Having said that, inland areas, especially those close to the slopes of Mount Gimie (950 metres or 3.120 feet high) experience even more rainfall.

That being said, though, the pattern of rainfall is the same across all Saint Lucia areas. So, the heaviest and most frequent rains are noticed between July and November, while the shorter and more sporadic rains usually happen in the period between February and April.

Using the previous comparison between Vieux fort and Castries to demonstrate the similarity in rain patterns across Saint Lucia, both regions’ least rainy months are February and March, while the rainiest ones are July through December.

Average precipitation (Castries)

Average number of rainy days per month (Castries)

Sunshine Hours

Despite the heavy and frequent rains the island has almost throughout the year, they don’t tend to affect the hours of sunshine Saint Lucia experiences. This could be attributed to the fact that the thunderstorms of downpours are intense but short-spanning. In fact, Saint Lucia enjoys a steady 8 hours of sunshine every single month, which is fantastic (especially for the coastal regions) compared to other Caribbean islands with much less sunshine throughout their days. The average monthly total is around 250 hours of sunshine, except for October and February (with 215 and 225 hours of sunshine, respectively), while the annual average is almost 2900 hours of sunshine!

Sunshine hours (Castries)

Sea Temperature

The sea is warm and inviting throughout the year, with water temperatures ranging between 27-28oC (80-85oF), which is fantastic for any water sports activity or other outdoor endeavour.

Sea temperature