St Lucia weather by month
St Lucia is warmest in September (30°C average high) and coolest in January (27°C). Rain is part of every month in St Lucia (at least 15 rainy days a month by our count). The driest months are February to April. The sea is warm enough for easy swimming all year.
Warmest month
September
30°C
Coolest month
January
27°C
Wettest month
July
25 rainy days
Flight from London
8½h
direct, estimated
St Lucia temperature by month
Tap a month for the detail and warmer alternatives.
When to go to St Lucia
What is the best month to visit St Lucia for sun?
Rain is part of every month in St Lucia (at least 15 rainy days a month by our count). The driest months are February to April.
What is the hottest month in St Lucia?
September averages 30°C. January is the coolest at 27°C.
When does it rain most in St Lucia?
July, with about 25 wet days.
When is the sea warm enough to swim in St Lucia?
all year, when the sea averages 21°C or more.
How we measured this
Daily averages from 2016 to 2025, from the Open-Meteo historical weather archive (ECMWF ERA5 reanalysis); sea temperatures are 2023 to 2025 averages from the Open-Meteo marine archive. A rainy day has at least 1 mm of rain.
Going to St Lucia?
Save the places you find on TikTok and Instagram for St Lucia to one map, and Dream Trip will plan the days around them.
