Bermuda’s climate is subtropical and influenced by two major factors: the Gulf Stream and the Bermuda–Azores High. Like a giant security blanket, the Gulf Stream flows northeast from the Gulf of Mexico—from which it takes its name—through the Straits of Florida to an area northeast of Bermuda, channeling warm equatorial water northward on its journey. The Gulf Stream moderates temperature, bringing mild weather throughout the year and preventing Bermuda from getting as hot or cold as mainland areas of the same latitude. Frost is not found here, though winter gets the occasional hailstorm.
The Bermuda–Azores High is a high-pressure zone, which also exerts a welcome influence on Bermuda’s climate. In the summer, the zone lies east of Bermuda, bouncing storm systems north of the island and causing light southerly winds to blow throughout the season. In the winter, though, the high sits too far southeast to make a difference, allowing northerly gales to pummel the island with cooler temperatures. Unlike the Caribbean, Bermuda has no trade winds or monsoons, and its isolated position brings a lower risk of hurricanes.
Officially, Bermuda has two seasons, summer and winter, which also define the tourism industry. Summer, the “high” season for visitors, runs April–October, while winter, once snubbed as the “off” or “low” season, runs November–March.
Most Bermudians, however, would argue the island actually does enjoy four seasons like its mainland counterparts. Locals can immediately discern the first breath of fall in the second week of October, when temperatures dip from the torpor of summer, or the sweet calm of spring in early April after the windy barrage of New Year storms.
The island has no rainy season; instead, rain tends to be spread throughout the year, with January being the wettest month on average, with 150 millimeters, or six inches of rain. Typically, even torrential rainstorms peter out after an hour or two, and rare are the days when the sun does not make a single appearance. The hour-by-hour changes can prove challenging to packing clothes for a Bermuda holiday in any season; choose a mix of outfits and layers to accommodate the unexpected.
True summer can be counted on May–September, with temperatures peaking in July and August. Relative humidity (ranging between 75 and 85 percent all year, but occasionally spiking to 90 in midsummer) makes Bermuda feel uncomfortably like a greenhouse, draining energy—and buckets of sweat—particularly in the summer. Hydration is key to doing anything active in these months, and swimming is the most refreshing way to cool off. October–December marks one of the most pleasant times of the year, when cool breezes prevail, but the sun can be hot enough that you’ll want to swim. The windy season usually takes control after Christmas, bringing storms, cold winds, rain, and damp days and nights from January to March; this is, perhaps, the most unpredictable season, for there can often be long spells of sunshine amid the tempestuousness. Ignore the euphemistic descriptions on tourist brochures, though; it can get very chilly by Bermudian standards, and many homes and hotels have no heating, aside from fires and electric heaters. Remember, too, a modest 60 degrees Fahrenheit can feel downright frigid if you happen to be driving a scooter on a windblown winter’s night; wear gloves like Bermudians do. Spring signals a drop in winds, and a resulting rebirth in garden growth and blossoms, as calm, sunny weather prevails and temperatures begin their inevitable rise toward the end of May. Bermuda Day (May 24) is the traditional first day of summer, though islanders usually refuse to swim until at least a month later.
Bermuda’s summer and winter temperatures differ considerably, though the yearly average is a balmy 76°F. Monthly variations are more telling: Average temperatures range from 66°F in February to 85°F in August, the effects heightened considerably by summer’s humidity. Annual lows and highs normally range from 55°F to 95°F.
Seawater temperatures hover around 65°F in the winter, but warm to a bath-like 83°F by August. Visitors often swim and scuba dive year-round, however.
Bermuda’s rainfall is fairly evenly distributed throughout the year, with no true rainy season, though rain is more likely to intrude on outdoor activities if you visit between January and March. Even then, Bermuda rainfall tends to come in the form of a quick downpour rather than daylong drizzle, so barring a hurricane, weather rarely ruins a Bermuda vacation. Indeed, it’s possible to have torrential rain in Paget, while St. Georgians simultaneously bask in the sun.
The hurricane season officially runs six months, June 1–November 30, but Bermudians consider themselves safe until the seawater temperature hits 85 degrees, usually in July, and it remains that warm through September.
Bermuda escapes most of the annual roster of storms, most of which miss the island due to its tiny landmass, though severe storms have scored direct hits—on average every half-dozen years. The last—and worst on record—was the Category 3 Hurricane Fabian, in 2003. More common are huge storm swells off the beaches, which whip up surf and prohibit swimming, and heavy rain and wind when hurricanes are in the vicinity. Storms have also spawned tornadoes that twist across isolated areas of the island, ripping off roofs before vanishing out to sea.
Hurricane near-misses have occurred some seasons, as these violent vortexes sideswipe the island; very rarely, hurricanes bounce back eastward after first careening towards the U.S. East Coast. Particularly after the fury of Fabian, however, Bermudians are highly aware of a hurricane’s destructive force and monitor the track of every single storm during this season, no matter how large, small, or apparently distant.
The government and media communicate the details of approaching storms, and Bermuda’s Emergency Measures Organization is well prepared to orchestrate recovery and clean-up efforts in the event of severe damage. After Fabian killed four Bermudians, the government has cracked down with stricter storm preparations, including closing the mile-long Causeway to St. George’s when big storms draw too close. Yet, Bermuda generally fares far better than Caribbean islands in the event of a direct hit, thanks to its sturdy limestone and cement-block buildings, well-developed infrastructure, and modern communications system. Most householders stock up every summer with hurricane supplies (tarps, flashlights, batteries, and buckets).
Emergency broadcasts by police and government media relations officers are made via 100.1 FM, when other stations are knocked off the air during power outages. Weather warnings, including marine forecasts, are broadcast by the Bermuda Weather Service (tel. 977, www.weather.bm), or via Bermuda Harbour Radio (www.rcc.bm). You can look up weather photos and climate data for any date since 1996 on www.bermudaweather.bm. During hurricane season, both the National Weather Service (www.nws.noaa.gov) and The Weather Channel (www.weather.com) track developing storms and their movements through the Caribbean and Atlantic with satellite images and forecasts.
Another useful site to visit to learn about hurricanes and Bermuda folklore is www.sharkoil.bm, named for the homespun meteorological indicators many locals still consult when bad weather looms. Even in the 21st century, orthodox science sometimes takes a backseat to these traditional barometers—sealed bottles of fatty hydrocarbons extracted from a shark’s liver. For centuries, Bermudians have hung “shark oil” in a sheltered spot outdoors, where they check its content to predict a storm’s ferocity. While younger generations now turn to CNN, old-timers swear the bottle’s contents turn cloudy during disturbances, and if a hurricane actually looms, a spiraling plume will be visible inside.
© Rosemary Jones from Moon Bermuda, 2nd Edition