The presence of the great mountain mass formed by the Himalayas and its spurs on the North and of the ocean on the South are the two major influences operating on the climate of India. The first poses an impenetrable barrier to the influence of cold winds from central Asia, and gives the sub-continent the elements of tropical type of climate. The second, which is the source of cool moisture-laden winds reaching India, gives it the elements of the oceanic type of climate.
India has a very great diversity and variety of climate and an even greater variety of weather conditions. The climate ranges from continental to oceanic, from extremes of heat to extremes of cold, from extreme aridity and negligible rainfall to excessive humidity and torrential rainfall. It is, therefore, necessary to avoid any genralisation as to the prevalence of any particular kind of climate, not only over the country as a whole but over major areas in it. The climatic condition influences to a great extent the water resources utilisation of the country.