The rising homogeneity of global crop supply has increased vulnerability to climatic and economic disruptions. While substantial work has examined yield variations in relation to climate variability, little is known about the influence of harvested area on production stability. To investigate this, here we take the example of monsoon cereal production in India, which has steadily shifted towards climate-sensitive rice and away from alternative cereals (finger millet, maize, pearl millet, and sorghum). We find that variations in harvested area are significantly associated with current and past price fluctuations for all cereals except rice. This suggests that farmer decisions based on economic factors may exercise great influence in determining variations in harvested area. We also show that optimized allocations of harvested area can reduce climate-induced production loss by 11% or improve farmer net profit by 11% while maintaining calorie production and cropland area. Such improvements would be possible by reducing harvested areas dedicated to rice and increasing areas allocated to alternative cereals. Our findings show that strategies using harvested area to address cereal yield fluctuations and improve farm profits could complement ongoing efforts to improve alternative cereal yields and stabilize cereal production.