Re-defining the Climatic Zones over Nigeria

Aims: This study aimed at identifying climatic zones over Nigeria.

Duration of Study: Daily air temperature data for the 36 states and FCT in Nigeria were obtained from National Aeronautic and Space Administration (NASA) for the period of thirty-seven (37) years (1984-2020).

Method: Several hierarchical clustering procedures–single linkages, complete linkage, average distance within clusters, average distance between clusters, centroid clustering, median linkage and Ward’s method were used in this study.

Results: Based on the findings, median linkage, complete linkage and Ward’s clustering method solutions seems more realistic. The application of cluster analysis, revealed five climate zones (cluster) over Nigeria. Cluster 1 covers Plateau state only while cluster 2 covers three south-west states and one north-west state (Kaduna). Cluster 3 covers all the states in south-east, south-south (except Cross River), North-central (except Kogi and Kwara), Bauchi in North-west and ogun and Oyo in South-west. Cluster 4 covers one state in south-south (Cross River), South-south (Lagos), two states in North-central (Kogi and Kwara), three states in North-east (Adamawa, Gombe and Taraba) and four states in North-west (Jigawa, Kano, Kastina and Zamfara). Lastly cluster 5 covers two states in North-east (Borno and Yobe) and North-west (Kebbi and Sokoto).

Conclusion: Our findings clearly show that cluster analysis can be applied to identify similar weather/climate state from air temperature data.