Most of Europe has a relatively mild climatewhich is largely due to its oceanic exposure to the north, west, and south. The east-west orien-tation of the mountains in Europe normally prevents extremely cold arctic air from penetrating southward to the Mediterranean. As a result, very cold weather is limited to the northern limits. The southern coast and Mediterranean countries enjoy moderate temperatures year round because relatively warm maritime air masses move inland from the Atlantic and because of the moderating influence of the Mediterranean Sea. However, this inflow of maritime air also brings frequent cloudiness, considerable precipitation, and high humidity.
When continental air masses dominate,Europe is subjected to low-temperature extremes, low humidity, and clear skies much the same as North America. This is especially true north of the Alpine Mountains. South of this region, somewhat normal migratory patterns do exist. The end result is relatively dry summers and wet winters characteristic of the western coastal region of North America and Canada. Temperatures are highest in Europe during the summer; Athens, Greece averages 80°F; Granada, Spain 77°F; Greenwich, England 63°F; and Paris, France 65°F Farther north, summer temperatures average as much as 20 to 25 degrees less. During the winter, the Medi-terranean temperatures average in the upper 40°F to low 50°F range while the extreme northern sections average 10°F or less. The Atlantic coastal countries with their predominantly maritime climates maintain far less temperature extremes between summer and winter. Precipitation in the form of rain and drizzle is common along the European Atlantic coast and near the Mediterranean Sea. Snow does occur at times in areas east of Spain and north of the Mediterranean Sea. At higher elevations inland, snow is common and frequently abundant. Central Spain and southern Russia, by contrast, experience semiarid and arid climates.
Asia’s climate is predominantly continental.The only exceptions are the heavily populated coastal areas that have tropical and maritime climates during the summer. This primarily con-tinental climate results in limited precipitation and large temperature ranges both daily and seasonally.
Asia is a huge continent with large expansesof land extending far northward. The Himalaya Mountains stretch across the southern portion in an east-west direction; mountains also parallel the eastern coast. These geographical features often contain continental arctic and polar air inland, resulting in the most extreme temperature ranges found in the Northern Hemisphere. Northeastern Siberia’s temperatures often range from –60°F in the winter to above 60°F in the summer. Extremes range as high as 98°F and as low as –90°F. The large interior of Asia also results in extreme pressure difference. In the winter the con-tinent is dominated by a cold high-pressure area and in the summer by a warm low-pressure area. This accounts for the northeast winter monsoons and southwest summer monsoons.
In the winter the interior is dry, receiving lessthan 1 inch of precipitation. Coastal areas under maritime influence receive normal amounts (about 8 inches) of precipitation. In the summer, precipitation is plentiful except well inland. Rain is so abundant in some regions, such as India, that the yearly rainfall average (425 inches or more) is among the highest in the world.
The extreme south and southeast regions ofAsia differ sharply from its northern neighbors. These southern regions enjoy the tropical and maritime climates that feature only minor seasonal temperature variations. Eastern Asia enjoys a climate very similar to that found along the eastern coast of North America from the Florida Keys to eastern Canada. East and southeast Asia, like the eastern and southeastern United States, is also subject to an occasional tropical cyclone (typhoon) in the summer and in the fall.
SOUTH AMERICAN WEATHER
South America has a variety of climates butlacks the severe weather of North America. Con-tinental polar air does not exist here because the continent tapers sharply from north to south. The larger northern area is close to the equator and does not experience the influx of cold maritime polar air from the south. Tropical climates prevail over much of the continent. Yet, due to the high Andes Mountains along the western coast, there are areas that are extremely dry and others that are extremely wet.
The South American northeast’s climate con-sistsmainly of high temperature and humidity and copious rainfall throughout the year. September is the warmest month with average temperatures of around 82°F. January is the coolest month with average temperatures of around 79°F. Nighttime temperatures rarely fall below 65°F. Rainfall averages 87 inches annually with 12 inches falling in June and just over 2 inches falling in October. The higher elevations of northeastern South America have greater ranges of temperature, humidity, and precipitation; however, these ranges are not extreme.
In the southern region, below 20° southlatitude, South America has distinct seasons very similar to those in the southeastern United States. These seasons, however, are reversed. The warmest month is January, which averages 74°F; July, which averages 49°F is the coolest month. Precipitation occurs fairly evenly throughout the year and averages 38 inches. There is no distinct rainy season.
Below 40° south latitude, the climate is pro-gressivelydrier and cooler. However, the extreme southern tip of South America is characterized by year round cold and damp climate due to a strong maritime influence.
West Coast Climate
The west coast, from northern Peru to themiddle of Chile, is a desert. North and south of this desert midsection, the climate is quite humid. The northwest coast has atypical tropical climate with wet and dry seasons, Below central Chile, the climate again shows atypical Southern Hemisphere seasonal reversal of that found in North America. The weather in this region is similar to that found along the northwest coast of North America. The climate is generally rainy and cool. Summer does not seem to exist as we know it. Yet, winter temperatures average above freezing.