The terrain characteristics of an area play vital role in the spatial and temporal behaviour of the hydraulic heads of groundwater body. The present study was carried out to understand the influence of major terrain parameters such as slope, drainage, geology and soil characteristics on the seasonal variations of the hydraulic head in the Kallada river basin, South Kerala, India. Water table was measured at 166 open wells in the study area during pre-monsoon and post-monsoon periods to accomplish the objectives. Hydraulic heads in the study area varied seasonally from 0 to 4.33m during the study period. Wells with very less change in hydraulic head fall in the midland area, where the drainage frequency is very low to low. Areas with very high slope are characterized by less recharge and the wells at such areas show highest change in hydraulic head. Also, the wells with higher variation in hydraulic heads are associated with Kodumon, Mynagapally and Ummannur soil series.