NIGERIAN CLIMATE

Overview: Although Nigeria lies wholly within the tropical zone, there are wide climatic variations in different regions of the country. Near the coast, the seasons are not sharply defined. Temperatures rarely exceed 32° C (90° F ), but humidity is very high and nights are hot. Inland, there are two distinct seasons: a wet season from April to October, with generally lower temperatures, and a dry season from November to March, with midday temperatures that surpass 38° C (100° F ) but relatively cool nights, dropping as low as 12° C (54° F ). On the Jos Plateau, temperatures are more moderate.

 

Average rainfall along the coast varies from about 180 cm (70 in) in the west to about 430 cm (170 in) in certain parts of the east. Inland, it decreases to around 130 cm (50 in) over most of central Nigeria and only 50 cm (20 in) in the extreme north.

 

Two principal wind currents affect Nigeria. The harmattan, from the northeast, is hot and dry and carries a reddish dust from the desert; it causes high temperatures during the day and cool nights. The southwest wind brings cloudy and rainy weather.

Source: Nations encyclopedia

Nigeria’s climate is moderated by its location. It 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. The country's geographic coordinates are http://upload.wikimedia.org/wikipedia/commons/thumb/5/55/WMA_button2b.png/17px-WMA_button2b.png10°00′N 8°00′E10°N 8°E.

 

Climate

Nigeria is found in the Tropics, making the country a tropical country with a tropical climate type where seasons are 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

1.      The Tropical rainforest climate or the Equatorial monsoon,   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 vapor in the rapidly rising air.

The Tropical rainforest climate has a very small temperature range. The temperature ranges are almost constant throughout the year

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 2,000 mm (78.7 in) rainfall totals giving for tropical rainforest climates worldwide. Over 4,000 mm (157.5 in) 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 4,000 mm (157.5 in) of rainfall annually. The rest of the southeast receives between 2,000 and 3,000 mm (118.1 in) of rain per year.

The southern region of Nigeria experiences a double rainfall maxima characterized 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.

2.      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 18 °C (64 °F) throughout the year. Abuja, Nigeria's capital city found in central Nigeria, has a temperature range of 18.45 °C (65.21 °F) to 36.05 °C (96.89 °F), and an annual rainfall of about 1,500 mm (59.1 in) with a single rainfall maxima in September.

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), 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 1,100 mm (43.3 in) in the lowlands of the river Niger Benue trough to over 2,000 mm (78.7 in) along the south western escarpment of the Jos Plateau and the southern Kaduna highlands which extents into Nigeria's Federal Capital Territory, just north of Abuja city, due to orographic activities on the highlands in central Nigeria.

3.      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 40 °C (104.0 °F)

4.      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 1,520 metres (4,987 ft) 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.

Seasons

Nigeria, like the rest of West Africa and other tropical lands, has only two seasons. These are the Dry season and the Rainy season.

The dry season is accompanied by a dust laden airmass from the Sahara Desert, locally known as Harmattan, or by its main name, The Tropical Continental (CT) airmass.

The rainy season is heavily influenced by an airmass originating from the south atlantic ocean, locally known as the south west wind, or by its main name, The Tropical Maritime (MT) airmass. These two major wind systems in Nigeria are known as the trade winds.

Temperature

Nigeria's location in the tropics has giving her a tropical hot climate. Temperatures in Nigeria varies according to the seasons of the year as with other lands found in the tropics. Nigeria's seasons are determined by rainfall with rainy season and dry season being the major seasons in Nigeria.

The rainy season of Nigeria brings in cooler weather to the country as a result of an increased cloud cover that acts as a blockage to the intense sunshine of the tropics by blocking much of the suns rays in the rainy season; this in turn cools the land, and the winds above the ground remains cool thereby making for cooler temperatures during the rainy season. But afternoons in the rainy season can be hot and humid, a feature of tropical climates.

 

The dry season of Nigeria is a period of little cloud cover in the southern part of Nigeria to virtually no cloud cover in the northern part of Nigeria. The sun shines through the atmosphere with little obstructions from the clear skies making the dry season in Nigeria a period of warm weather conditions. In the middle of the dry season around December, a dusty wind from the Sahara Desert called the harmattan enters Nigeria from the northeastern part of the country blocking sun rays partially from shining and also creating haze in the atmosphere, this activities of the wind lowers temperatures considerably saving inhabitants for sometime, from the scorching heat that would have occurred as a result of clearer skies during the dry season. But with the withdrawal of this wind around March to April following the unset of the rainy season, temperatures can go as high as 44 °C (111.2 °F) in some parts of Nigeria.

Semi temperate weather conditions prevail on the highlands in central Nigeria above 1,200 metres (3,937 ft) above sea level, namely the Jos Plateau. Temperatures on the Jos plateau ranges between 21°C to 25°C which are cool all year round.

Temperate weather conditions occur on the highlands along the Nigeria Cameroon border, in the eastern part of Nigeria. Highlands in these region attain an average height of more than 1,524 m (5,000 ft) to some standing above 2,000 metres (6,562 ft) above sea level. The climate on these highlands is temperate all year round. The major highlands in this region are the Obudu Plateau above 1,584 m (5,197 ft) , Mambilla Plateau above 1,524 m (5,000 ft) and Mt Chappal Waddi above 2,000 m (6,562 ft).

Vegetation

Nigeria is covered by three types of vegetation:

1.      Forests (where there is significant tree cover),

2.      Savannahs (insignificant tree cover, with grasses and flowers located between trees), and

3.      Montane land. (The latter is the least common, and is mainly found in the mountains near the Cameroonian border.) Both the forest zone and the savannah zone are divided into three parts.

Some of the forest zone's most southerly portion, especially around the Niger River and Cross River deltas, is mangrove swamp (see Central African mangroves). North of this is fresh water swamp, containing different vegetation from the salt water mangrove swamps, and north of that is rain forest.

The savannah zone's three categories are divided into mm' Guinean forest-savanna mosaic, made up of plains of tall grass which are interrupted by trees, the most common across the country; Sudan savannah, similar but with shorter grasses and shorter trees; and Sahel savannah patches of grass and sand, found in the northeast.

Source: wikipedia.org