Scotland has a temperate oceanic climate, milder than might be expected from its latitude. Despite its small area, there are considerable variations. Precipitation is greatest in the mountainous areas of the west, as prevailing winds, laden with moisture from the Atlantic, blow from the southwest. East winds are common in winter and spring, when cold, dry continental air masses envelop the east coast. Hence, the west tends to be milder in winter, with less frost and with snow seldom lying long at lower elevations, but it is damper and cloudier than the east in summer. Tiree, in the Inner Hebrides off the west coast, has a mean temperature in winter of 41 °F (5 °C) in the coldest month (as high as southeastern England), whereas Dundee, on the east coast, has 37 °F (3 °C). Dundee’s mean temperature in the warmest month is 59 °F (15 °C) and Tiree’s 57 °F (14 °C). There is a smaller range of temperatures over the year in Scotland than in southern England. Precipitation varies remarkably. Some two-thirds of Scotland receives more than 40 inches (1,000 mm) annually, the average for Britain, with the total reaching 142 inches (3,600 mm) in the Ben Nevis area and somewhat more near Loch Quoich farther to the northwest. In the flat Outer Hebrides conditions are less humid, as in the east, where the Moray Firth receives annually less than 25 inches (635 mm) and Dundee less than 32 inches (810 mm). A significant amount of snow falls above 1,500 feet (460 metres) in the Highlands in winter.

Plant and animal life

Lower elevations, up to about 1,500 feet, were once covered with natural forests, which have been cleared over the course of centuries and replaced in some areas by trees, plants, and crops. Survivals of the original forest are found sporadically throughout the Highlands—for example, in the pinewoods of Rothiemurchus in the Spey valley. Grass and heather cover most of the Grampians and the Southern Uplands, where the soil is not so wet and dank as in the northwestern Highlands. Shrubs such as bearberry, crowberry, and blaeberry (bilberry) grow on peaty soil, as does bog cotton. Alpine and Arctic species flourish on the highest slopes and plateaus of the Grampians, including saxifrages, creeping azalea, and dwarf willows. Ben Lawers is noted for its plentiful mountain flora.

Scotland is rich in animal life for its size. Herds of red deer graze in the corries and remote glens; although formerly woodland dwellers, they are now found mainly on higher ground, but roe deer still inhabit the woods, along with sika and fallow deer (both introduced species) in some areas. Foxes and badgers are widespread, but the Scottish wildcat has become critically endangered as a result of disease and interbreeding with domestic cats. Rabbits were once decimated by the disease myxomatosis but have largely recovered to earlier numbers. Pine marten, otters, and mountain and brown hares are among other wild mammals. A few ospreys nest in Scotland, and golden eagles, buzzards, peregrine falcons, and kestrels are the most notable of resident birds of prey. The red grouse, the Scottish subspecies of the willow grouse, has long been hunted for sport. Other species of grouse include the ptarmigan, found only at higher elevations, and the large capercaillie, which has been reintroduced into Scotland’s pine woodlands. Large numbers of seabirds, such as gannets, fulmars, guillemots, and gulls, breed on cliffs and on the stacks (isolated rocks) around the magnificent coasts. More than one-third of the world’s Atlantic, or gray, seals breed in Scottish waters, especially around the Northern and Western Isles, as do numerous common seals; dolphins and porpoises are regularly seen and whales occasionally, especially on the west coast.