St Lucia weather in December
St Lucia averages 28°C by day and 24°C at night in December, with the sea at 28°C and 19 days with at least 1 mm of rain.
Day
28°C
Night
24°C
Sea
28°C
Rainy days
19
Flight from London
8½h
What December feels like
December is hot but wet in St Lucia: rainy season, so pack for showers.
The sea is warm at 28°C: comfortable for long swims.
It is rainy season, with rain on about 19 days.
Of the 48 sun destinations we track, St Lucia is the #16 warmest in December.
Want it warmer in December?
These are hotter than St Lucia this month for at most an hour and a half more flying:
St Lucia weather by month
December is highlighted. Compare with November and January, or see the full year in St Lucia.
St Lucia in December: quick answers
Is St Lucia hot in December?
December is hot but wet in St Lucia: rainy season, so pack for showers. Average highs are 28°C and lows 24°C.
Can you swim in St Lucia in December?
The sea is warm at 28°C: comfortable for long swims.
Does it rain in St Lucia in December?
It is rainy season, with rain on about 19 days.
What is the warmest month in St Lucia?
September, at an average high of 30°C. The coolest is January at 27°C.
How long is the flight to St Lucia from the UK?
About 8½h direct from London, estimated from the 6,769 km distance. Check your airline for exact times.
Still choosing? See where is hot in December for every destination ranked by temperature, sea and flight time.
How we measured this
Averages of every day in December from 2016 to 2025, from the Open-Meteo historical weather archive (ECMWF ERA5 reanalysis). Sea temperature is the 2023 to 2025 average from the Open-Meteo marine archive. A rainy day has at least 1 mm of rain. Reanalysis describes an area about 25 km across, so sheltered resorts can run a degree or two warmer. Flight time is a distance-based estimate from London Heathrow.
Planning St Lucia in December?
Save the restaurants, beaches and views you find on TikTok and Instagram for St Lucia straight to a map, then let Dream Trip turn them into a day-by-day plan.
