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 about 71 mm of rain in the month.
Day
28°C
Night
24°C
Sea
28°C
Rain
71 mm
Flight from London
8½h
What December feels like
December is hot in St Lucia: proper beach weather.
The sea is warm at 28°C: comfortable for long swims.
Rain is occasional: about 71 mm in the month.
That is 19°C warmer than an average December day in London.
Of the 56 sun destinations we track, St Lucia is the #19 warmest in December.
Comparing places? See which Caribbean island is warmest in winter for every winter month, place by place.
Going to St Lucia in December?
Share the TikToks and Instagram Reels you've saved for St Lucia to Dream Trip. It finds the places, pins them on a map and builds your days around them.
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.
| Month | Day | Night | Sea | Rain |
|---|---|---|---|---|
| January | 27°C | 24°C | 28°C | 70 mm |
| February | 27°C | 24°C | 27°C | 54 mm |
| March | 28°C | 24°C | 27°C | 55 mm |
| April | 29°C | 25°C | 28°C | 45 mm |
| May | 29°C | 25°C | 28°C | 61 mm |
| June | 29°C | 25°C | 29°C | 107 mm |
| July | 29°C | 25°C | 29°C | 129 mm |
| August | 30°C | 26°C | 30°C | 118 mm |
| September | 30°C | 26°C | 30°C | 109 mm |
| October | 29°C | 26°C | 30°C | 108 mm |
| November | 29°C | 25°C | 29°C | 113 mm |
| December | 28°C | 24°C | 28°C | 71 mm |
St Lucia in December: quick answers
Is St Lucia hot in December?
December is hot in St Lucia: proper beach weather. 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?
Rain is occasional: about 71 mm in the month.
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. Rain is the average monthly total. 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.
