We want to thank Mr René Fury, from Météo France, for his help with the information below
In St Barts, temperatures vary very little, from 20°C/68°F to 33°C/91,4°F. During the coolest time of the year, the temperature might go down to 19°C/66,2°F at night, while the record cold stands at 18°5C/65,3°F. Average temperatures are 21°C/69,8°F in the winter, and 25°5°C/77,9°F in the summer. The highest temperatures hover around 30°C/86°F in February and 33°C/91,4°F in the hottest months, with record highs reaching 35°C/95°F.
Ocean temperatures vary from a low of 26°C/78,8°F in February to more than 29°C/84,2°F in the summer.
Rains are unpredictable and it can rain quite a bit in just a few days. The annual level of rainfall is fairly stable yet affected by the passage of tropical storms. The annual average has not varied too much, at least during the second half of the 20th century or throughout the past century in general. The island generally gets between 750mm/30” and 1115mm/44” of rain per year, in at least 80% any given years. The 20% of the years where there is less than 750mm/30” or more than 1115mm/44” of rain are exceptional.