Understanding the interactions of atmospheric variables and biological systems in agriculture, and applying this knowledge to improve productivity is critical. One of the most vulnerable sectors to changes in environmental conditions is rainfed agriculture because of limited and unreliable rainfall. Minor coarse grain crops such as oats, barley and minor millets (finger millet, fox tail millet, kodo millet, and proso millet) are primarily grown under rainfed conditions and in marginal lands of temperate, arid and semiarid regions. Yield potential of these crops is low compared to other cereals; however, they have unique nutritional qualities. Understanding growth and development stages and climatic requirements is important for development of best and efficient management practices. Oats are a cool climate crop and hence, are susceptible to hot and dry weather from heading until grain filling period. Barley can be grown during summer and winter seasons and is highly sensitive to frost at all growth stages. Minor millets are relatively more resilient to extreme climatic conditions, compared to other cereals. The area under cultivation of these coarse cereals is declining due to, non-availability of high yielding varieties, limited crop management options, high labor involved in their processing and negative perceptions of minor millets as a food for the poor relative to other crops; and limited support and procurement policies. The importance of minor millets for global food and nutritional security is increasing due to medicinal and nutritional properties and tolerance to abiotic and biotic stress.