In direct contrast with climate, in which short-term variations disappear with the calculation of averages, the weather of the British Isles is notoriously variable. Not only is it liable to day-to-day changes- some whole seasons are markedly wet, markedly dry, unusually cold, or unusually warm.
Spring is normally Britain's driest season, even though April is by tradition showery. Cold weather usually lasts no later than mid-April, and there are frequently some very warm days during the second half of the month. By late spring daytime temperature rises considerably, and the thermometer may even reach 2I-24°C over a wide area.
June is the brightest month of the year for Britain in general. Rainfall tends to increase during July and August, partly because Atlantic depressions some nearer to the coast during these months and partly also because air, as it becomes warmed, is capable of holding more moisture. Late summer is often noted for vary warm weather, and this way continue into September.
North and north-west winds often bring heavy falls of snow to north Britain during late October and November, but they are usually short-lived.
Continental air sometimes reaches the British Isles in summer as a warm, dry air-stream, but it is more frequently experienced in winter when it crosses the North Sea and brings bitter weather to eastern and inland districts of Great Britain.
In fine, still weather there is occasionally haze in summer and mist and fog in winter.