Bermuda

Bermuda does not actually have a tropical climate at any time of year. It is often described as having a sub-tropical climate, but that is not a genuine climate type, simply a term that is better for tourism than a relatively warm temperate climate. There are many such terms used in describing aspects of Bermuda that are not actually true, starting with references to its being in the Caribbean or West Indies, and including references to its being a coral island; of coral rock; with houses built of coral, and roads lined with coral walls. Bermuda is noted for having the most northerly coral reef on Earth, but it is not the most northerly place where coral is found. The reef is not formed primarily by coral, but by other calcium secreting organisms, like algae. Bermuda is actually a limestone island (a sandstone limestone upper layer, a solid limestone layer below, and finally the volcanic rock of the seamount below). That limestone was formed by foraminifera, not by coral...but coral sounds more in keeping with the image of a tropical island so beloved by tourism ministers. I digress...

Bermuda has an Oceanic Climate. This is also known as a West Coast Climate...in the Northern Hemisphere. An oceanic climate is characterised by humid air. Air changes temperature quickly, heating rapidly with the rise of the sun, but cooling as quickly as the heat source is removed. Water, by comparison, heats slowly, but acts as a heat sink, and cools as slowly after the heat source is removed. High relative humidity has a stabilising effect on air temperatures, keeping the temperature range more moderate, and also slowing the pace of heating and cooling.

This is why the warmest time of the year in Bermuda is late July, early August, rather than at summer solstice (late June), and also why temperatures in early June in Bermuda are much lower than areas like New York, or New England. In fact, the highest temperature reached in Bermuda in a typical year will be 30° C/86° F in July and August, much lower than in New York, for instance, which may see temperatures around 100° F (well over Bermuda's record high). North Carolina may experience temperatures of 115° in June, when temperatures in Bermuda may still be between the upper 'sixties and mid 'seventies.

The reverse is also true...winter temperatures in Bermuda are not as cold. No one who has wintered there would say that there is no winter...average temperature during the winters is probably in the 'Sixties, and the lowest temperatures most years will be in the 'fifties...in February/March, again, two months after the (winter) solstice. Although ice storms and other freezing conditions have been experienced in Bermuda in recorded history (hail is not uncommon, and blanketted the island like snow in the winter of 1985), for the last century, at least, the actual temperature has stayed above freezing....but, with the powerful winds and heavy rainfall taken into effect, felt temperatures have been known to drop below freezing.

Global warming has definitely been noticeable in Bermuda since the late 1980s, but the climate is still a long way from being tropical.

Due to the mean wind direction in the Northern Hemisphere being to the East, West coasts of continents generally share Bermuda's oceanic climate, though the temperature ranges vary depending how far north or South you are. It explains the temperate rainforest found in Washington State, British Columbia, and Southern Alaska. Ireland and Britain, kept warm and humid by the wind off the Gulf Stream (which also keeps Bermuda above freezing in the winter) also have moderate ranges of temperature, and relatively humid and wet climates. This is also why Europe, generally, is so warm compared to the same latitudes on the Atlantic Seaboard of North America. Finland has the largest forest in Europe. The same latitude in Canada is pretty much above the tree line. Snow will fall as far South in North America as Florida and Alabama (both further South than Bermuda)...about the same latitude as the Canary Islands, or Cairo, Egypt. Glasgow, in Scotland, by comparison (where the average winter temperature is about 4° C, and the lowest temperatures are typically about 0° C in February, and which sees little snow) is about the same latitude as Goose Bay, Newfoundland (averaging -23.3° C in January).

In Bermuda, the decisive factors on felt temperature are the wind, rain, humidity, and degree of overcast. Its never safe to assume you will see clear sunny days during the summer, or overcast ones during the winter. Wind is pretty much always a safe assumption. The summers can be intolerable if there is no overcast, and if the humidity is high. We lower our temperature through evaporative cooling, and if the relative humidity is near 100%, we cannot lose body heat. The air over Bermuda is generally clear, so when there is no cloud cover in summer, the Sun can be merciless. Stepping into shade, however, can make it immediately apparent that the ambient temperature is much lower than what might be assumed in the full glare of the Sun. Historically, Bermuda was heavily forested with cedars. these kept sunlight off, and moderated temperatures. 8 million of these trees were lost to a blight that resulted from the building of US airbases during the war (scale mites were introduced in the process). Although other tress were imported and quickly spread to replace the cedars, the population has doubled, since, and sprawled sith the legalisation of motor vehicles, drastically reducing the forested area. A series of powerful storms have felled many of the large introduced trees, which were not suitable for Bermuda's stormy climate. Consequently, shade may be harder to find than it used to be. In the winter, with cold fronts sweeping from the Arctic air mass over Canada every few days, temperatures can vary rather dramatically from day to day. After a front sweeps through, the air is usually colder and much drier. This is Bermuda's normal weather characteristic, but, during the summer, the local high pressure effect is strengthened, the arctic air mass contracts, and the cold fronts are weakened, all of which work to lessen the effect the cold fronts have at that time of year.