Climate and Weather in Great Britain (Климат и погода в Великобритании)

Climate and Weather in Great Britain

Weather is not the same as climate. The weather at a place is the

state of the atmosphere there at a given time or over a short period. The

weather of the British Isles is greatly variable.

The climate of a place or region, on the other hand, represents the

average weather conditions over a long period of time.

The climate of any place results from the interaction of a number of

determining factors, of which the most important are latitude, distance

from the sea, relief and the direction of the prevailing winds.

The geographical position of the British Isles within latitudes 50o to

60o N is a basic factor in determining the main characteristics of the

climate. Temperature, the most important climatic element, depends not

only on the angle at which the sun’s rays strike the earth’s surface, but

also on the duration of daylight. The length of day at London ranges from

16 hours 35 minutes on June to 7 hours 50 minutes on 21 December. British

latitudes form the temperate nature of the British climate, for the sun is

never directly overhead as in the tropical areas.

Britain’s climate is dominated by the influence of the sea. It is much

milder than that in any other country in the same latitudes. This is due

partly to the presence of the North Atlantic Drift, or the Gulf Stream, and

partly to the fact that north-west Europe lies in a predominantly westerly

wind-belt. This means that marine influences warm the land in winter and

cool in summer. This moderating effect of the sea is in fact, the cause of

the relatively small seasonal contrasts experienced in Britain.

The moderating effect of the ocean on air temperature is also stronger

in winter than in summer. When the surface water is cooler than the air

above it – as frequently happens during the summer months – the air

tends to lose its heat to the water. The lowest layers of air are chilled

and become denser by contradiction, and the chilled air tends to remain at

low levels. The surface water expands because it is warmed, and remains on

the surface of the ocean. Unless the air is turbulent, little of it can be

cooled, for little heat is exchanged.

Opposite conditions apply in winter. The air in winter is likely to be

cooler than the surface water, so that the heat passes from water to air.

Air at low levels is warmed and expands and rises, carrying oceanic heat

with it, while the chilled surface water contracts and sinks, to be

replaced by unchilled water from below. This convectional overturning both

of water and of air leads to a vigorous exchange of heat.

The prevailing winds in the British Isles are westerlies. They are

extremely moist, as a result of their long passage over warm waters of the

North Atlantic. On their arrival to Britain, the winds are forced upwards,

and as a result large-scale condensation takes place, clouds form and

precipitation follows, especially over the mountainous areas.

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 winds from the east sometimes reach the British Isles in summer

as a warm, dry air-stream, but they are more frequently experienced in

winter when they cross the north sea and bring cold, continental-type

weather to eastern and inland districts of Great Britain.

Relief is the most important factor controlling the distribution of

temperature and precipitation within Britain. The actual temperatures

experienced in the hilly and mountainous parts are considerably lower than

those in the lowlands. The effect of relief on precipitation is even more

striking. Average annual rainfall in Britain is about 1,100 mm. But the

geographical distribution of rainfall is largely determined by topography.

The mountainous areas of the west and north have more rainfall than the

lowlands of the south and east. The western Scottish Highlands, the Lake

District (the Cumbrian mountains), Welsh uplands and parts of Devon and

Cornwall in the south-west receive more than 2,000 mm of rainfall each

year.

In contrast, the eastern lowlands, lying in a rain-shadow area, are

much drier and usually receive little precipitation. Much of eastern and

south-eastern England (including London) receive less than 700 mm each

year, and snow falls on only 15 to 18 days on the average.

Rainfall is fairly well distributed throughout the year, although

March to June are the driest months and October to January are the wettest.

Ireland is in the rather a different category, for here the rain-

bearing winds have not been deprived of their moisture, and much of the

Irish plain receives up to 1,200 mm of rainfall per year, usually in the

form of steady and prolonged drizzle. Snow, on the other hand, is rare,

owing to the warming effects of the Gulf Stream. The combined influences of

the sea and prevailing winds are equally evident in the general pattern of

rainfall over the country.

Because of the North Atlantic Drift and predominantly maritime air

masses that reach the British Isles from the west, the range in temperature

throughout the year is never very great. The annual mean temperature in

England and Wales is about 10oC , in Scotland and Northern Ireland about

9oC. July and August are the warmest months of the year, and January and

February the coldest.

The mean winter temperature in the north is 3OC,the mean summer

temperature 12oC. The corresponding figures for the south are 5oC and 16oC.

The mean January temperature for London is 4oC, and the mean July

temperature 17oC.

During a normal summer the temperature may occasionally rise above

30oC in the south. Minimum temperatures of –10oC may occur on a still clear

winter’s night in inland areas.

The distribution of sunshine shows a general decrease from south to

north – the south has much longer periods of sunshine than the north.

It is frequently said that Great Britain does not experience climate,

but only weather. This statement suggests that there is such a day-to-day

variation in temperature, rainfall, wind direction, wind speed and sunshine

that the “average weather conditions”, there is usually no very great

variation from year to year or between corresponding seasons of different

years.

No place in Britain is more than 120 km from the sea. But although the

British are crowded very closely in a very small country, there is one

respect in which they are very fortunate. This is their climate. Perhaps,

this is a surprising statement because almost everyone has heard how

annoying the weather usually is in England. Because of the frequent clouds

and the moisture that hangs in the air even on fairly clear days, England

has less sunshine than most countries, and the sunlight is weaker then in

other places where the air is dry and clear. What is worse, sunshine rarely

lasts long enough for a person to have time to enjoy it. The weather

changes constantly. No ordinary person can guess from one day to another

which season he will find himself in when he wakes in the morning.

Moreover, a day in January may be as warm as a warm day in July and a day

in July may be as cold as the coldest in January.

But although the English weather is more unreliable than any weather

in the world, the English climate – average weather – is a good one.

English winters are seldom very cold and the summers are seldom hot. Men

ride to work on bicycles all through the year. Along the south coast

English gardens even contain occasional palm trees.

The most remarkable feature of English weather, the London fog, has as

exaggerated reputation. What makes fog thick in big industrial areas is not

so much the moisture in the air as the soot from millions of coal fires.

Such smogs (smoke + fog) are not frequent today. Since 1965 as a result of

changes in fuel usage and the introduction of clean air legislation, they

have become less severe. It is quite natural that in fine, still weather

there is occasionally haze in summer and mist and fog in winter.

The amount of rainfall in Britain is exaggerated, too. Britain seems

to have a great deal of rain because there are so many showers. But usually

very little rain falls at a time. Often the rain is hardly more than

floating mist in which you can hardly get wet. Although a period of as long

as three weeks without rain is exceptional in Britain.

It is no wonder that, living in such an unbearable climate with so

many rules and with still more exceptions, the Englishmen talk about their

weather, whatever it may be, and their climate, too.

Literature

1.Baranovski L.S., Kozikis D.D.. How Do You Do, Britain? – Moscow

,1997.