This page was going to be called The Climate of Scotland, until we remembered the popular saying: "Scotland doesn't have a climate, just weather!" Actually, you can learn quite a lot by listening to what Scots say about their weather. Some are pessimists like the comic who declared: "Scotland only has two seasons, July and Winter!" Perhaps the most accurate insight on offer is a little more balanced: "If you don't like the weather in Scotland, just wait five minutes or move five miles, and you'll get different weather."
Scotland does have a climate of course. Technically it can be described as "temperate maritime": or, to put it another way, the weather here is rarely extreme, but can be extremely changeable.
Given that Scotland lies on much the same latitude as Moscow and Labrador, winters are rather milder than you might expect, because of the warming effect of the Atlantic's Gulf Stream. Though it does tend to be colder than the rest of the UK, and at times can get very cold. The UK's lowest ever recorded temperature was -27.2°C, at both Braemar in Aberdeenshire on 10 January 1982 and Altnaharra in Highland on 30 December 1995.
More usually, average winter maximum daytime temperatures are between 5°C and 6°C, and average summer maximum daytime temperatures are between 15°C and 17°C. The maximum temperature ever recorded in Scotland was 32.9°C, on 9 August 2003 at Greycrook in the Scottish Borders.
Rainfall amounts vary significantly across Scotland. In parts of the Western Highlands, rainfall can exceed 3000mm each year as warm, wet air flowing in from the Atlantic is forced to rise to higher altitude by the region's mountains, where it cools and condenses, causing rain. On the other hand, parts of eastern Scotland have as little as 800mm rainfall each year. Typically, measurable rain can occur on as many as 250 days each year in the Highlands, compared with 175 days on the coasts of Angus, Fife and East Lothian. The comparable figure for the driest places in south-east England is 150 days. On the other hand, Scotland's average of 3-9 days per year on which thunderstorms are experienced, compares favourably with England's 9-15 days.
Scotland has traditionally been known as a venue for winter climbing and winter sports more widely. Recent years have seen less snowfall than the longer term average, which can see sleet or snow falling on up to 100 days in parts of the Grampians. The least snowfall is experienced by areas along the west coast, with snow falling on as few as 20 days each year. The presence of snow, both falling and laying, also varies considerably with altitude as average temperatures drop by about 2°C for each 1,000ft climbed.
Transport problems caused by severe winter weather have been a relative rarity in recent years, but the areas most prone to disruption are generally those exposed to the colder air coming in from the east across the North Sea: with Easter Ross, Aberdeenshire and Angus usually being first in the firing line. Scots know that the usual first sign of winter's arrival is when Radio Scotland's traffic news announces that the B974 Cairn O'Mount road From Fettercairn to Banchory has been closed by snow. This road, totally exposed to weather from the east and climbing to nearly 1,500ft, is always the first to close and the last to be opened.
Amounts of sunshine can also vary considerably across Scotland. Parts of the north-west can have average annual sunshine totals of between 700 and 1,000 hours, while parts of Angus, Fife, the Lothians, Ayrshire, and Dumfries and Galloway average over 1,400 hours of sunshine per year. Scotland's sunniest city is Dundee. The sunniest individual location is often the Hebridean island of Tiree which managed 329 hours of sunshine during May 1946 and again in May 1975. At the other extreme Cape Wrath, in the far north-west of Sutherland, had a total of just 0.6 hours of sunshine in January 1983.
When thinking about light it also pays to remember that day length varies significantly with latitude. In June there is up to 4 hours more daylight in Lerwick, Shetland, than in London. On the other hand, in December there is be up to 4 hours less daylight in Lerwick than in London.
As in the rest of the UK, the prevailing wind across Scotland is from the west or south-west. Because of their lack of shelter, some of the UK's windiest places are in Scotland, and the Western Isles, Orkney and Shetland each have over 30 days of gales every year. The - unofficial - record for UK windspeed was 177mph, measured in the winter of 1962 on the top of Saxa Vord, the highest hill on Unst, the most northerly of the Shetland Islands: just as the recording equipment blew away.
Given that the weather can have such a major influence on our day to day experience of Scotland and its landscape, it is a shame that the reliability of weather forecasts is not as good as most visitors to the country will be used to, whether they are from across the Atlantic, from mainland Europe, or from England. The problem lies in the fact that Scotland's weather is simply so changeable: forecasting techniques that work well for much of the UK simply fall short when applied to Scotland, especially during periods when change is taking place. Anyone staying in Scotland who watches the BBC National and BBC Scotland weather forecasts on Breakfast TV has to be struck by the frequency with which the Scottish element of the UK forecast is simply inconsistent with the more detailed separate Scottish forecast. And all too often neither turns out to be consistent with the weather that actually turns up later that day.
And, finally... If you had a free choice, when would be the best time of year to visit Scotland? Without any hesitation we'd recommend May, with June as a second choice. The weather tends to be at its best in terms of most sunshine and least rainfall (though not highest temperatures); the days are extremely long; the visitor attractions are open, yet visitors are still relatively thin on the ground; and, especially if you are visiting the Highlands, the midges have not yet made their presence felt.