Assessment of Monthly Rainfall Profile for Umudike, Abia State, Nigeria

Rainfall is the climate variable of primary importance in shaping the spatial and temporal variations of agriculture in the tropics. The seasonal cycle of rainfall directly determine the tempo and rhythm of agriculture through its limitation on the length of the growing season. The start of the rain in the tropics is seldom abrupt, but is usually foreshadowed by a succession of isolated showers of uncertain intensity with intervening dry period of varying duration (Ojo, 1977, Ati, 2002). The break of the rainy season may be early in some years, greatly delayed in others (Bationo et al, 1997). Monthly rainfall OF 1977-2017 (40 years) obtained from the National Root Crops Research Institution Umudike, Abia state, Nigeria is used for this study. Results are presented in tables and subjected ton statistical analysis using a trend analysis, the Person’s Product Moment correlation and Analysis of variance. The findings indicate that April and October are the onset and cessation months (dates) of rains for the study area. The mean SD of the rainfall variable across the months of the years indicates that September is the month with the highest mean rainfall (333.1020.51mm), followed by June, July, August, and May (303.5126.11, 301.1817.73, 290.1828.16 and 283.6828.72mm) respectively, while December and January shows the least mean rainfall of 5.041.96 and 14.477.06mm respectively. The length of rainfall days also indicates that August, September and July has the highest month with the days of rainfall with 20.460.86, 20.230.69, and 20.230.92mm, followed by the months June, October, and may with days of rainfall of 16.690.60, 16.380.82 and 15.230.53mm respectively while the month January and December has the lowest days of rainfall of 1.000.29 and 0.760.23mm respectively. Based on the findings of the work, study made some recommendations such as educating of farmers on consequences of climate variability on crop production, and to ensure that peasant farmers get the yearly weather forecast prior to planting season, which are considered as a major policy implications.