Destination guide
St Lucia weather by month
February is the best time to visit St Lucia for the balance of warmth, sunshine and fewer rainy days, with January and March close behind. February brings daytime temperatures of 27°C, around 10 rain days and 7 hours of sunshine a day. Warmth is reliable throughout the year; the bigger decision is how much rain you are prepared to work around. Later months suit travellers who can keep outdoor plans flexible rather than depend on dry weather.
- Hottest month
- 29.2°CSeptember
- Coolest month
- 27.0°CJanuary
- Warmest sea
- 29.0°CSeptember
- Flight from London
- 9 h 12 minLong-haul (7 h+) · estimated
St Lucia, month by month
A little perspective
St Lucia through the year
Every month at a glance; "best" marks our three top months on warmth, dryness and sunshine.
| Month | Day | Night | Sea | Sun/day | Rain mm | Rainy days | Days 25°C+ |
|---|---|---|---|---|---|---|---|
| Januarybest | 27.0°C | 23.5°C | 27.0°C | 7.1 | 36 | 13 | 99% |
| Februarybest | 27.4°C | 23.3°C | 26.6°C | 7.2 | 25 | 10 | 99% |
| Marchbest | 27.9°C | 23.5°C | 26.7°C | 6.7 | 30 | 11 | 100% |
| April | 28.5°C | 24.1°C | 27.1°C | 5.8 | 39 | 12 | 100% |
| May | 29.1°C | 24.8°C | 27.6°C | 5.2 | 51 | 13 | 100% |
| June | 29.0°C | 25.0°C | 27.8°C | 4.8 | 68 | 16 | 100% |
| July | 28.8°C | 24.9°C | 28.0°C | 5.8 | 89 | 21 | 100% |
| August | 29.0°C | 25.1°C | 28.6°C | 5.6 | 101 | 21 | 100% |
| September | 29.2°C | 25.2°C | 29.0°C | 4.6 | 106 | 20 | 100% |
| October | 28.7°C | 25.0°C | 28.9°C | 4.5 | 118 | 21 | 100% |
| November | 28.0°C | 24.5°C | 28.4°C | 5.3 | 103 | 20 | 100% |
| December | 27.5°C | 24.0°C | 27.7°C | 6.4 | 46 | 14 | 100% |
Day = average daytime high, night = average night-time low, 1991-2020.Sun is hours per day; rainy days count 1 mm or more.
Day, night and sea
Monthly average temperatures, 1991-2020
- Day
- Night
- Sea
Best months here
On warmth, low rainfall and sunshine, start with these.
When to go to St Lucia
For beach weather, look at months where the daytime average clears 25°C and rainy days stay low: January, February, March, April, May, June, July, August, September, October, November, December. October is the wettest month (118 mm, about 21 rainy days) and February the driest (25 mm). The sea is warmest in September at 29.0°C and coolest in February at 26.6°C.
Getting there
A direct flight from London Gatwick to Hewanorra International Airport (UVF, 30 km from Castries) takes roughly 9 h 12 min - long-haul (7 h+) by UK standards. Time-zone: America/St Lucia.
Records and extremes, 1991-2020
The hottest day recorded in St Lucia between 1991 and 2020 reached 32.0°C on 21 September 2020; the coldest fell to 20.2°C on 23 February 2018. In September one day in ten tops 30.4°C and about 25% of days pass 30°C; in January one night in ten drops to 22.5°C or below. The wettest single month of the period was October 2010 with 341 mm, against a October average of 118 mm.
Sunrise, sunset and daylight in St Lucia
Local time on the 15th of each month; daylight-saving rules as of 2020.
| Month (15th) | Sunrise | Sunset | Daylight | Sunshine/day |
|---|---|---|---|---|
| January | 06:32 | 17:55 | 11.4 h | 7.1 h |
| February | 06:28 | 18:09 | 11.7 h | 7.2 h |
| March | 06:12 | 18:14 | 12.0 h | 6.7 h |
| April | 05:51 | 18:17 | 12.4 h | 5.8 h |
| May | 05:37 | 18:24 | 12.8 h | 5.2 h |
| June | 05:36 | 18:33 | 12.9 h | 4.8 h |
| July | 05:44 | 18:36 | 12.9 h | 5.8 h |
| August | 05:51 | 18:26 | 12.6 h | 5.6 h |
| September | 05:53 | 18:06 | 12.2 h | 4.6 h |
| October | 05:55 | 17:45 | 11.8 h | 4.5 h |
| November | 06:04 | 17:33 | 11.5 h | 5.3 h |
| December | 06:20 | 17:38 | 11.3 h | 6.4 h |
January to April: the strongest choice for outdoor plans
January and February have daytime averages of 27°C, rising to 28°C in March and April. This is the most appealing stretch if you want warm days without choosing the hottest part of the year. February has the fewest rain days, while January and March share its 7 hours of daily sunshine. April remains a reasonable choice, though sunshine slips to 6 hours and rain days edge up from March. Pack light clothing for the daytime and something for rain rather than assuming every day will stay dry. Nights remain warm, so this period suits travellers who dislike cool evenings as much as those seeking daytime warmth.
May to August: warmer days, with more rain to work around
May marks a warmer stretch, with daytime averages of 29°C and nights at 25°C through August. Light, loose clothing makes sense, and shade breaks are a sensible part of midday plans. May has 13 rain days, increasing to 16 in June and 21 in July and August, so waterproof protection becomes more useful as this period progresses. July and August offer more sunshine than June, but not fewer rainy days: brighter conditions do not mean a reliably dry visit. The sea warms from 28°C to 29°C by August. Choose this stretch for warm water and evenings, accepting that outdoor plans may need changing.
September to December: warm seas, then improving conditions
September is the hottest month, although its rounded daytime average of 29°C matches the preceding months. October brings the clearest catch: it is the wettest month and averages just 4 hours of sunshine a day. September and November also have frequent rain, so this stretch is less suited to a holiday built around dependable dry weather. The sea stays at 29°C through October before easing to 28°C in November and December. December offers a more favourable balance, with 14 rain days and 6 hours of sunshine. It is a reasonable alternative to the early-year favourites, provided you still leave room for wet-weather changes.
A little more detail
St Lucia weather FAQs
Plain answers, grounded in the averages.
What is the best time to visit St Lucia?
Judged on warmth, low rainfall and sunshine, the best months in St Lucia are February, March and January. September is the hottest month (average high 29.2°C) and January the coolest (27.0°C).
How many months a year is St Lucia over 25°C?
12 months in St Lucia average a daytime high of 25°C or more, and 12 average 20°C or more.
When is the rainy season in St Lucia?
October is the wettest month in St Lucia (118 mm on average) and February the driest (25 mm). Annual rainfall averages 812 mm.
What is the hottest temperature recorded in St Lucia?
The hottest day recorded in St Lucia between 1991 and 2020 reached 32.0°C on 21 September 2020; the coldest fell to 20.2°C on 23 February 2018. Records come from daily data for 1991-2020, not from a single station's all-time history.
Is the sea warm enough for swimming all year?
Sea temperatures stay between 27°C and 29°C throughout the year, so cold water is unlikely to be the deciding factor. August, September and October have the warmest sea, but the early-year months combine warm water with fewer rainy days.
Will I need warm clothes in the evenings?
Average night temperatures range from 23°C in February to 25°C from May through October. Light evening clothing should generally be suitable outdoors. If you dislike warm nights, the early-year months offer slightly cooler conditions, rather than a genuinely cool season.
How long is the flight from London?
The flight from London takes about 9 hours 12 minutes, making St Lucia a long-haul choice. If dependable outdoor weather is central to that journey, February, March and January offer the strongest balance of sunshine, warmth and fewer rainy days.
See also: St Lucia weather by month · where else is hot in September
About these averages
ERA5-Land climate reanalysis via Open-Meteo (11 km grid) and NOAA Coral Reef Watch 5 km sea temperatures, 1991-2020
Averages computed from daily values at Castries. Sea temperature from the nearest 5 km sea cell, 3.1 km from that point. Sunshine hours are estimated from average cloud cover.Records are the highest and lowest daily values in that 30-year period, not all-time records. These are climate averages, not a forecast for your trip. How we measure holiday weather
- Hot · 25°C+
- Warm · 20°C to below 25°C
- Mild · 15°C to below 20°C
- Cool · below 15°C