What's The Weather Like In Saint Barts?

St Barthelemy, usually written St Barts, sits in the Caribbean at about 17.9 degrees north, and its weather is the classic tropical-marine pattern: warm every month, a drier stretch in late winter and spring, and a wetter stretch from late summer into autumn. The Meteo-France normals for the St Barthelemy station, covering 1991 to 2020, give the island a mean daily high of 28.5 C in January and 31.7 C in September; annual rainfall totals 891.3 mm, and October is the wettest month at 135.6 mm. Those four numbers describe the whole climate. The rest of this page unpacks them month by month, explains where the Atlantic hurricane season sits in the calendar, and covers the sea temperature, which stays warm enough for swimming year-round.

What's The Weather Like In Saint Barts?

St Barts is warm year-round with mean daily highs between 28.5 C in January and 31.7 C in September, according to the Meteo-France normals for 1991 to 2020, and it receives 891.3 mm of rain a year, with October the wettest month at 135.6 mm. There is no cold season, no month that needs more than a light layer, and the main weather divide is between the drier winter half of the year and the wetter late-summer and autumn months.

That divide matters more than any single temperature. From December through April the island sits in the dry Caribbean winter: rain totals run from 38.4 mm in February to 79.2 mm in December, and mean daily highs hold steady. From August through November the totals climb, peaking in October, and the same months carry the highest hurricane-season risk. Temperatures barely move across the whole year: the spread between the coolest mean high (January, 28.5 C) and the warmest (September, 31.7 C) is barely more than three degrees.

For planning purposes the question is rarely "will it be warm" because it always will be. The question is how much rain and storm risk you accept, and whether the hotel and restaurant calendar is fully open when you land, since many properties close in the autumn shoulder period and reopen between mid-October and early November.

How Warm Is St Barts Month By Month?

Mean daily highs in St Barts run from 28.5 C in January and 28.6 C in February to 31.7 C in September, with mean daily lows from 23.3 C in February to 26.3 C in August, per the Meteo-France normals for 1991 to 2020. Every month of the year averages a high above 28 C, so the island never has an off-season for temperature.

The month-by-month detail comes straight from the Meteo-France normals for the St Barthelemy station:

Two patterns stand out. Nights stay warm: even in February, the coolest month, the mean daily low is 23.3 C, so an evening in Gustavia needs nothing warmer than short sleeves. And the rain distribution is lopsided: February's 38.4 mm is the lowest monthly total, while October's 135.6 mm is more than three times that, and November's 118.6 mm is the second wettest.

That rain pattern, not temperature, is what shapes the high season. The months with the lowest totals, February through April, are the months when the island's hotel and restaurant calendar is at its fullest, and when the sailing events such as the St Barths Bucket Regatta in mid-March take place. If you are weighing a winter trip against a summer one, the companion page on St Barts weather by season carries the same figures broken into season blocks.

A day on the water is the other place the weather matters directly, and the marine layer is part of the forecast too: the environment agency's regulatory-zones page imposes a 5-knot speed limit inside reserve waters around Colombier and Ile Fourchue, so a sailing day there is a slow, calm-water day by design. The group sail that visits those bays from St Martin runs per-person trips, and its calendar on the listing shows the seasonal window, from 12 May to 31 August 2027, with live dates and pricing on the operator's page.

When Is Hurricane Season In St Barts?

The Atlantic hurricane season runs from 1 June to 30 November, with the peak from mid-August to mid-October and the climatological peak of activity near 10 September. October (135.6 mm) and November (118.6 mm) are the two wettest months in the Meteo-France normals, and the wet autumn overlaps the hurricane season.

The season is long but back-loaded. June and July sit inside the official season yet post modest rain totals in the normals, 56.0 mm and 80.4 mm respectively, and mean highs around 31 C. The risk climbs through August and concentrates in September and the first half of October. Hurricane Irma, the storm most associated with the island, struck in September 2017.

The National Hurricane Center publishes a tropical weather outlook for the Atlantic basin, and Météo-France's vigilance system covers Saint-Martin and Saint-Barthélemy; both are the references to watch if travelling in the peak months. The St Barts nature reserve waters stay open year-round, but sea state can change any boat day regardless of season.

The autumn overlap matters for trip logistics, not just weather. Many hotels and restaurants close for an autumn break and reopen in waves between mid-October and early November, so a late-October visit lands right on the reopening boundary, while November travel means rain totals are still high but the island is largely back in operation, including the St Barth Gourmet Festival from 9 to 15 November 2026. For a fuller discussion, see the St Barts hurricane season picture on the season page.

How Warm Is The Sea Around St Barts?

Sea temperature around St Barts runs about 26 C in winter to about 29 C from August to October, per a secondary climate source, so the water is warm enough for swimming in every month of the year. There is no month when the sea is cold, and no wetsuit is needed for snorkelling.

Those figures are rounded and secondary rather than station normals, so write them as approximations: about 26 C in the winter months, rising to about 29 C from August through October. The warmest sea and the warmest air arrive together, which is why late-summer swimmers get the warmest water of the year even as the rain totals climb.

The sea-state side of the forecast matters for the crossing from St Martin as much as for swimming: the ferry runs from Philipsburg and Marigot to Gustavia and the crossing can be rough when conditions are up, so the sea, not the air temperature, is the weather variable that most often changes a plan.

Which Months Suit Which Kind Of St Barts Trip?

December through April pairs the lowest rain totals in the Meteo-France normals, 38.4 mm in February to 79.2 mm in December, with mean highs of 28.5 C to 29.8 C, making it the fullest-calendar stretch; May through July is warmer, near 31 C, with moderate rain; and September through November is the wettest and storm-peak period, with 96.9 mm to 135.6 mm a month.

A rough planning grid, using only the normals:

The dry winter months carry the busiest calendar: the Music Festival runs 8 to 18 January 2027, the Bucket Regatta is mid-March, and New Year's Eve brings its annual fireworks over Gustavia harbor. Spring adds Les Voiles de St Barth in April and the Film Festival in late April or early May. Summer is quieter on land but is the per-person sailing window: the group sail's listing shows 12 May to 31 August 2027 for its shared departures from St Martin.

Whatever the month, the days run on the same clock: St Barts keeps Atlantic Standard Time year-round with no daylight saving, so the sunset moves only slightly through the year; the time difference in Saint Barts page covers it in detail, and the sunset spots around St Barts hold in every season. More on the whole island picture sits on St Barthelemy Travel's season guide.

Does It Ever Get Cool Or Rain All Day In St Barts?

No month in the Meteo-France normals averages a daily low below 23.3 C, so St Barts never has cool weather, and no month averages more than 135.6 mm of rain, spread across the month rather than falling in one unbroken stretch. Rain typically arrives in short, heavy tropical showers rather than long gray days, and the figures are monthly averages, not daily forecasts.

That distinction between a monthly total and a daily pattern is the practical one. A month with 60 mm of rain can still deliver long sunny spells; the totals simply rise through the autumn. Conversely the dry months are not rain-free, since even February averages 38.4 mm.

For what the weather lets you do with a day, the public beaches are open year-round and free, and the boat trips from St Martin run through the calendar outside their own seasonal windows. If a day turns wet, the island's indoor options are modest in scale, from the Wall House Museum in Gustavia to the shops around the harbor, and the rainy-day itinerary page lists them in order.

Common Questions About St Barts Weather

What's The Weather Like In Saint Barts?

Warm all year: Meteo-France normals for 1991 to 2020 give mean daily highs from 28.5 C in January to 31.7 C in September, with 891.3 mm of rain a year and October the wettest month at 135.6 mm.

When is the best time of year to visit St Barts?

December through April pairs the lowest monthly rain totals, 38.4 to 79.2 mm in the normals, with highs in the upper twenties Celsius and the fullest hotel, restaurant and event calendar. May through July is warmer with moderate rain and fewer crowds on the books.

Does it rain every day in St Barts in the wet season?

No. The monthly totals, which peak at 135.6 mm in October in the Meteo-France normals, are monthly sums; rain in the tropics typically falls in short heavy showers with sunny spells between, not all-day rain.

Is the sea warm enough to swim in winter?

Yes. Sea temperature around St Barts is about 26 C in winter and about 29 C from August to October per a secondary source, warm enough for swimming in every month.

Should I worry about hurricanes when booking St Barts?

The season runs 1 June to 30 November with the peak from mid-August to mid-October and the climatological peak near 10 September. Check the National Hurricane Center outlook and your own travel insurance terms when booking inside the peak.

Does St Barts get cold at night?

No. The lowest mean daily low in the normals is 23.3 C in February, and August averages 26.3 C overnight, so evenings stay warm throughout the year.

For the money-page view of the island across every season, the things to do in St Barts roundup carries the full calendar of beaches, harbor walks and boat days, and the month-by-month pages under the season guide extend the normals table above with what is open and what is running in each stretch of the year.