Weather in St. Barthelemy in September
Country-wide climate normals across 13 cities in St. Barthelemy.
How Hot Is St. Barthelemy in September?
Uniform heat across St. Barthelemy's September: averages climb to 29°C nationally with overnight lows of 27°C, narrow spread from coast to interior. The hottest cities like Toiny register similar readings to the coolest, so plan for consistently hot weather across the country.
Sunshine in St. Barthelemy in September
St. Barthelemy sees limited sun in September: just 1.8h a day in Gustavia, with heavy cloud cover common across most regions. Daylight runs from 6:00 am to 6:10 pm, but persistent grey skies and overcast stretches mean direct sunlight is genuinely scarce. Many days pass without any prolonged sunny spells.
Does It Rain In St. Barthelemy In September?
St. Barthelemy's September is wet across most regions: 140mm in Gustavia across 17 days, with rain falling on most days of the month. Coastal and highland regions can see significantly more, while interior regions may stay slightly drier. Sunny stretches are brief and uncommon.
Is St. Barthelemy Humid In September?
Heavy oppressive humidity covers St. Barthelemy in September: 76% on average in Gustavia, and similar saturating conditions exist nationwide. The air feels thick and heavy from sunrise to sundown, with little overnight respite. Coastal and tropical regions feel especially stifling.
Wind In St. Barthelemy In September
Breezy conditions cover St. Barthelemy's September: Gustavia sits at 27 kph on average, with the country as a whole feeling windy through the day. Afternoon winds pick up across most cities, and coastal regions often run significantly higher.
Cloud Cover In St. Barthelemy In September
Cloudy skies dominate St. Barthelemy in September — 73% cover in Gustavia, with similar overcast conditions in most regions. Direct sun is patchy and broken; expect grey stretches between brief bright moments. Coastal areas may be heavier than inland.