Complex sentence: This wind (the Tropical Maritime Airmass) invades the country from February in the southern part of Nigeria while it takes longer for the wind to fully cover the whole of the country, reaching the northern part of Nigeria in June.
Split into simpler sentences: This wind (the Tropical Maritime Airmass) invades the country from February, in the southern part of Nigeria. While it takes longer for the wind to fully cover the whole of the country, reaching the northern part of Nigeria in June.