Marginal farmers in rain-fed agrarian systems can benefit immensely from real-time contingency planning and decisionmaking tools in the climate milieu. Long-term climate anomaly prediction of some selected locations was made. Forty-two Global Circulation Models (GCM) from the Coupled Model Intercomparison Project Phase 5 project (CMIP5) were used for the present work and Representative Concentration Pathway (RCP) 4.5 to prepare future projections. The effect of the climate anomaly on existing farming practices in two selected climate-vulnerable locations of Purulia, India, and Shyamnagar, Bangladesh, has been analysed. A participatory action research and Climate Information Network (CIN)-based crop calendar has been devised for the selected locations. An interactive Android bot in the form of a Decision-Making Cropping Support System (DMCSS) has been devised and field tested. This system can provide seasonal crop suggestions and suggest contingency management to farmers. The system also provides risk assessments on the basis of preparedness and categorical inputs that users provide on crop, climate and contrivances.