Farming by resource-poor and inadequately informed farmers with fixed best-bet strategies under seasonal variability and changing climate in the semi-arid Central Rift Valley of Ethiopia has often proven to be of very low flexibility. While, struggling to survive in the face of high risks, farmers in semi arid-arid areas need flexible seasonal adaptation strategies. The “Response Farming” (RF) methodology, a system that derives forecast of seasonal rainfall from very early rain occurrences, and makes choices of crops and practices to conform to the forecasts was evaluated. The potential of RF in improving traditional adaptation measures employed to current rainfall variability and to observed and projected climate change was investigated. RF turned out superior to both research and farmers’ production strategies. Our evaluation of climate variability and change interventions (RF) show that adaptation strategies, based on RF modeling using long-term weather records, to be useful keys for improving traditional adaptation strategies and to make farming ecologically sustainable and economically feasible as climate change unfolds.