By Faith Ijeh
Harmattan season which occurs between the end of November and the middle of March is characterised by the dry and dusty northeasterly trade wind which blows from the Sahara Desert over West Africa into the Gulf of Guinea. The temperature is cold in most places, but can also be hot in certain places, depending on local circumstances.
The Harmattan blows during the dry season, which occurs during the months with the lowest sun.
Temperatures can easily be as low as nine degree Celsius all day, but sometimes in the afternoon the temperature can also soar to as high as 30 degree Celsius , while the relative humidity drops under 5 per cent. It can also be hot in some regions, especially in Sahara Desert.
The Harmattan brings desert-like weather conditions. It lowers the humidity, dissipates cloud cover, prevents rainfall formation and sometimes creates big clouds of dust which can result in dust storms or sandstorm. The wind can increase fire risk and cause severe crop damage. The interaction of the Harmattan with monsoon winds can cause tornadoes.
1. It happens only in West Africa.
The cool dry air that appears to be a worldwide phenomenon only affects the countries in West Africa. It is unique, as it is the only season collectively experienced by West Africa.
2. Harmattan winds blow from Sahara Desert.In the Sahara Desert, the air is so dry that heat escapes rapidly at night, leading to freezing temperatures. But during the day, the heat in its potential is saturated.
3. Temperatures get low and high. Temperature difference is another feature of Harmattan. During Harmattan, the winds in the morning and at night become cold, and at daytime gets hot. It is colder in the morning, as the winds blow more.
4. Harmattan wind is called ‘The Doctor.’
The name ‘The Doctor’ was given to the wind that accompanied Harmattan, due to is invigorating dryness.
5. Harmattan haze is harmful to health. The heavy amount of dust in the air which is like a heavy fog is known as Harmattan haze. It can severely limit visibility and block the sun for several days. This usually cost airlines millions of dollars in cancelled and diverted flights each year.
When humidity drops to as low as 15 per cent, it can result in spontaneous nosebleeds for some people. Other health effects on humans may include dryness of the skin, dried or chapped lips, eyes, and respiratory system- running nose, coughing, sneezing including aggravation of asthma.
NIGERIA 
