There are two major seasons in the climate of Nigeria. The rainy season and the dry season (popularly known as harmattan season). Rainy season in Nigeria is usually between November and March of while the dry season is between November and March.
The dry season is very cold in the mornings and evenings. The mornings are especially cold before sunrise. The season is characterised by cold weather, low humidity, dust particles suspended in air, blue cloudless sky and drought caused by absence of rainfall.
All these characteristics of the dry season are collectively known as Harmattan. Harmattan is caused by North east winds that blow in from across the Sahara desert. This makes the effects of Harmattan like drought, low humidity and cold temperature to be more pronunced in the northern parts of Nigeria.
Tourists and visitors to Nigeria and other countries that experience Harmattan should first check with the necessary authorities before proceeding on their journey to these countries.
Tourists and visitors that are asthmatic should seek medical advice before going to the northern part of the country.
Those that are allergic to dust or pollen should also seek medical advice before proceeding to the northern part of the country. This is due to high concentration of dust particles in the air in the northern parts.
Lots of fluid should be taken to compensate for loss of water from the body into the atmosphere through respiration.
Pilots should also take note that visibility is reduced due to high concentration of dust particles in the air which may sometimes impede air travel.