The research examined farmers' perception and adaptation strategies to rainfall variability in northwestern Katsina. The objectives were to determine the level of rainfall variability using 1976 to 2015 rainfall data; find-out farmers' perceptions of rainfall variability; determine its effects on farming activities, and identify adaptation strategies within the farming systems. Rainfall data were sourced and established (Rainfall Variability Index, RVI of 1.6) to support the farmers' perception of very high variability. Some 385 questionnaires were administered to sampled farmers using Krejcie and Morgan's (1970) from nine selected wards. SPSS (16.0) was used to analyze the results. Findings indicated main adaptation strategies to rainfall variability employed were mixed cropping; use of early maturing crops; irrigation and Fadama farming against rain-fed agriculture; use of chemical fertilizers; reducing landarea of production; abandonment of agricultural activities or; selling of assets. It was concluded that rainfall characteristics negatively affect crop yields and the adaptation strategies have positive contributions to production. It is recommended that farmers should adapt efficient water harvesting techniques; planting of drought-resistant and early-maturing crops as well as dry-planting. Government, on the other hand, should intensify on small irrigation schemes, promote agricultural extension services, and invest in soil-water conservation.