Saint-Barthelemy weather

Our guide to the weather in Saint-Barthelemy during September

29

Average high

6

UV Index

173mm

Monthly rainfall

77%

Humidity

We've looked at the most up-to-date weather data for Saint-Barthelemy, covering the last 12 years up to 2024, plus we've asked our team of travel bloggers for their first-hand experiences in order to answer the most frequently asked questions about Saint-Barthelemy weather in September.

How warm is it in Saint-Barthelemy during September?

September is typically the hottest month in Saint-Barthelemy. The temperature hits about 29℃ during the day, falling away to a balmy 28℃ at night. Of course, the high humidity will make it feel even hotter. The UV index will be high at this time of year, so protection against skin and eye damage is needed. Try to limit exposure between 10am and 4pm. Apply broad spectrum SPF 30+ sunscreen every few hours, even if it's cloudy, or more frequently after sweating or swimming, and wear UV-blocking sunglasses too, and bear in mind that bright surfaces, such as sand and water increase UV exposure.

Does it rain in Saint-Barthelemy during September?

On average, there will be 8 rainy days during the month, amounting to 173.2mm in total. That's a significant amount of rain. For comparison, the wettest months in the UK typically sees between 80mm and 100mm, depending on where you are. Due to the high temperature and humidity, you might expect lots of thunderstorms, however they're actually fairly infrequent at this time of year. On average, September will see just 4 days that produce a storm.

Is it windy in Saint-Barthelemy during September?

You're unlikely to experience any strong winds. Expect a gentle breeze that increases to moderate at times during September. The high humidity and warm temperature will make the breeze feel warm, so any cooling effect will be limted.

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Weather in Saint-Barthelemy

Our month-by-month guide to the weather and climate in Saint-Barthelemy

26.0

Saint-Barthelemy weather in

January
25.8

Saint-Barthelemy weather in

February
25.6

Saint-Barthelemy weather in

March
26.2

Saint-Barthelemy weather in

April
27.0

Saint-Barthelemy weather in

May
27.8

Saint-Barthelemy weather in

June
28.1

Saint-Barthelemy weather in

July
28.5

Saint-Barthelemy weather in

August
28.7

Saint-Barthelemy weather in

September
28.5

Saint-Barthelemy weather in

October
27.7

Saint-Barthelemy weather in

November
26.7

Saint-Barthelemy weather in

December