Rainfall seasonality in the Niger Delta Belt, Nigeria

This paper examined rainfall seasonality in the Niger Delta, Nigeria, using both monthly and annual rainfall data from 1931 to 1997. The data was retrieved from the archives of the Nigerian Meteorological Agency in Lagos. The data was collected on 9 synoptic stations in the region. The statistical tools employed for the study are the cumulative index analysis and the percentage of mean. The result indicated a wet season with over 95% of the total annual rainfall in the area. It also showed a long wet season from February/March to November and a short dry season from December to January/February. Besides, this study observed a northward increase in rainfall in part of the eastern side of the Niger Delta. The variation of rainfall in this locality could probably be as a result of rainfall determinant factors different from the inter tropical discontinuity. This study is important for agricultural planning and other socio-economic activities.   Key words: Annual rainfall, wet season, dry season, seasonality.