This article examines the seasonal variations in groundwater quality along the northern coastal stretch of Kerala using physicochemical and geophysical methods. During the pre-monsoon, monsoon, and post-monsoon seasons of 2018, thirty groundwater samples were collected from various geomorphological units to understand the groundwater quality and the effect of seawater intrusion. Physicochemical parameters viz., pH, electrical conductivity (EC), total dissolved solids (TDS), salinity, calcium (Ca2+), magnesium (Mg2+), sodium (Na+), potassium (K+), sulfate (SO42-), chloride (Cl-), total hardness (TH) and total alkalinity (TA) were determined and results were compared with the drinking water standards of BIS (2012) and WHO (2006). Physicochemical studies show seasonal variations in the quality of groundwater in the study area. Subsurface resistivity layers have been identified in geophysical surveys. Among eight locations surveyed for electrical resistivity, two showed good groundwater quality. The fresh-salt water interface in the study area varies from 0.9m to 42.4m meters in the pre-monsoon season and from 38.9m to 41.5m in the post-monsoon season.