Bermuda has a humid subtropical climate on the border of tropical climate. It is warmed by the nearby Gulf Stream, due to the westerlies, which carry warm, humid air eastwards over Bermuda, helping to keep winter temperatures above freezing. The climate is humid and, as a result, the summertime heat index can be high, even though mid-August temperatures rarely exceed 30 °C (86 °F). Winters are mild and windy, with average daytime temperatures in January and February around 20 °C (68 °F), although cold fronts bring Arctic air masses that can result in rapid temperature drops. Atlantic winter storms, often associated with these cold fronts, can produce powerful, gusting winds and heavy rain. Factoring in the wind chill, the felt air temperature in winter can fall below freezing, 0 °C (32 °F), even though the actual temperature rarely drops below 10 °C (50 °F). The lowest temperature recorded between 1949 and 1999 was 6.7 °C (44 °F), in February 1950.
Bermuda is very susceptible to hurricanes. Its position along the Gulf Stream means that it is often directly in the path of hurricanes recurving in the westerlies, although they have usually begun to weaken as they approach the island. It is often affected by these hurricanes, although the island's small size means that direct landfalls are rare. The last hurricane to cause significant damage to Bermuda was category 3 Hurricane Fabian on 5 September 2003.
The only source of fresh water in Bermuda is rainfall, which is collected on roofs and catchments (or drawn from underground lenses) and stored in tanks. Each dwelling usually has at least one of these tanks forming part of its foundation.
Average annual temperature of the sea is 23 °C (73 °F), from 20 °C (68 °F) in January to 28 °C (82 °F) in August
