The USA is the fourth largest country in the world, after Russia, Canada and China. Including the states of Alaska and Hawaii, the US covers an area of 9 millions square km.
I am going to tell you about the climate in the USA. The United States has many kinds of climate. The weather ranges from the warm, wet conditions of the Appalachians to the semi-desert or desert conditions in some of the western states.
It varies from southern Arizona and southern Florida, where almost there is no winter at all, to the territory of Montana, North Dakota and South Dakota, where there are long, very cold and severe winters. In other words, the US has practically all the climatic zones.
The main land mass of the US is in the temperate zone. The climatic conditions of the country are determined by the great mountains and the wind.
West of the Rocky Mountains, running all the way from the Canadian border to Mexico, there are vast areas where almost no trees grow. In this section of the country there are deserts, which receive as little as 12-13 centimetres of rainfall a year. Yet, west of the Sierra Nevada Mountains, there are places in which 250 centimetres of rain fall annually. It is one of the wettest places in the USA.
There are all kinds of differences in the climate of the US. For instance, all along the western coast, the temperature changes little between winter and summer. In some places, the average difference between July and January is as little as 10 degrees Centigrade. The climate along the northern part of this coast is similar to that of England.
But in the north central part of the country the temperature difference between winter and summer is very great — 36 degrees Centigrade and even more. The coldest days of January may be — 40 degrees Centigrade, and the hottest July days may be 45 degrees. In the eastern part of the US, the difference between summer and winter is also very distinct, but not so extreme.
In the south-eastern corner of the country the climate is mild and spring is like winter, but in summer the temperature may be very high.
Hawaii, the 50th state, is a chain of over 100 islands, lying in the Pacific and stretching from southeast to northwest for 2,575 kilometres. Although this state is located in tropical zone, its climate is favourable, because of the ocean currents that pass its shores and the winds that blow across the land from the northeast. The temperature usually remains close to the annual average of 24 degrees Centigrade.
The situation in Alaska is different. In those parts of the state which lie above the Arctic Circle, Alaska still is a land of icebergs and polar bears. Ice masses lie buried in the earth, which is permanently frozen land to a depth of 90 or more meters.
From early May until early August, the midnight sun never sets on this flat, treeless region, but the sun cannot melt the icy soil more than two thirds of a meter down. The Japan Current of the Pacific warms Alaska, and the Arctic cools it. The temperature may drop as low as — 43 degrees Centigrade in some places, and may drop to 30 degrees in others. In the north, in any given year, more than 11 meters of snow may fall.
