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Nigeria is a country in West Africa. Nigeria shares land borders with the Republic of Benin in the west, Chad and Cameroon in the east, and Niger in the north. Its coast lies on the Gulf of Guinea in the south and it borders Lake Chad to the northeast. Noted geographical features in Nigeria include the Adamawa highlands, Mambilla Plateau, Jos Plateau, Obudu Plateau, the Niger River, River Benue and Niger Delta. Nigeria is found in the Tropics, where the climate is seasonally damp and very humid. Nigeria is affected by four climate types; these climate types are distinguishable, as one moves from the southern part of Nigeria to the northern part of Nigeria through Nigeria's middle belt. == Climate types found in Nigeria == The Tropical monsoon climate, designated by the Köppen climate classification as "Am", is found in the southern part of the country. This climate is influenced by the monsoons originating from the South Atlantic ocean, which is brought into the country by the (maritime tropical) MT airmass, a warm moist sea to land seasonal wind. Its warmth and high humidity gives it a strong tendency to ascend and produce copious rainfall, which is a result of the condensation of water vapour in the rapidly rising air.〔http://www.britannica.com/EBchecked/topic/390302/monsoon〕 The Tropical monsoon climate has a very small temperature range. Then temperature ranges are almost constant throughout the year, for example, Warri town in the southern part of Nigeria, records a maximum of for its hottest month while its lowest temperature is in its coldest month. The temperature difference of Warri town is not more than 2 °C (5 °F). The southern part of Nigeria experiences heavy and abundant rainfall. These storms are usually convectional in nature due to the regions proximity, to the equatorial belt. The annual rainfall received in this region is very high, usually above the rainfall totals giving for tropical rainforest climates worldwide. Over of rainfall is received in the coastal region of Nigeria around the Niger delta area. Bonny town found in the coastal region of the Niger delta area in southern Nigeria receives well over of rainfall annually. The rest of the southeast receives between 2,000 and of rain per year. The southern region of Nigeria experiences a double ''rainfall maxima'' characterised by two high rainfall ''peaks'', with a short dry season and a longer dry season falling between and after each peaks. The ''first rainy season'' begins around March and last to the end of July with a peak in June,this rainy season is followed by a short dry break in August known as the ''August break'' which is a short dry season lasting for two to three weeks in August. This break is broken by the ''Short rainy season'' starting around early September and lasting to Mid October with a peak period at the end of September. The ending of the short rainy season in October is followed by ''Long Dry Season''. This period starts from late October and lasts till early March with peak dry conditions between early December and late February.〔http://www.cometonigeria.com/nigeria/climate.html〕 The Tropical savanna climate or Tropical wet and dry climate, is extensive in area and covers most of Western Nigeria to central Nigeria beginning from the Tropical rainforest climate boundary in southern Nigeria to the central part of Nigeria, where it exerts enormous influence on the region. This climate, the tropical savanna climate exhibits a well marked rainy season and a dry season with a single peak known as the ''summer maximum'' due to its distance from the equator. Temperatures are above throughout the year. Abuja, Nigeria's capital city found in central Nigeria, has a temperature range of to , and an annual rainfall of about with a single rainfall maxima in September.〔http://iahs.info/redbooks/a281/iahs_281_277.pdf〕 The single Dry season experienced in this climate, the tropical savanna climate in central Nigeria beginning from December to march, is hot and dry with the Harmattan wind, a continental tropical (CT) airmass laden with dust from the Sahara Desert prevailing throughout this period. With the Intertropical Convergence Zone (ITCZ) swinging northward over West Africa from the Southern Hemisphere in April, heavy showers coming from pre-monsoonal convective clouds mainly in the form of ''squall lines'' also known as the north easterlies formed mainly as a result of the interactions of the two dominant airmasses in Nigeria known as the Maritime tropical(south westerlies) and the Continental tropical(north easterlies),〔http://www.springerlink.com/content/w33602907w473v31/〕 begins in central Nigeria while the Monsoons from the south atlantic ocean arrives in central Nigeria in July bringing with it high humidity, heavy cloud cover and heavy rainfall which can be daily occurrence lasting till September when the monsoons gradually begin retreating southward to the southern part of Nigeria.Rainfall totals in central Nigeria varies from in the lowlands of the river Niger Benue trough to over along the south western escarpment of the Jos Plateau. The Sahel Climate or Tropical dry climate, is the predominant climate type in the northern part of Nigeria. Annual rainfall totals are lower compared to the southern and central part of Nigeria. Rainy season in the northern part of Nigeria last for only three to four months (June–September). The rest of the year is hot and dry with temperatures climbing as high as . ''Alpine climate or highland climate or mountain climate'', are found on highlands regions in Nigeria. Highlands with the alpine climate in Nigeria, are well over above sea level. Due to their location in the tropics, this elevation is high enough to reach the temperate climate line in the tropics thereby giving the highlands, mountains and the plateau regions standing above this height, a ''cool mountain climate''. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Geography of Nigeria」の詳細全文を読む スポンサード リンク
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