In Himalaya, food security mainly depends on local agricultural productivity, community food purchasing power, and infrastructural facilities for transportation and distribution of food. Due to limitations of terrain, subsistence agriculture constitutes the main source of rural food and livelihood. The constraints of subsistence economy compel a large proportion of rural youth-male population to migrate out of the region in search of livelihoods. This paper examines the impact of climate change on food security through interpreting linkages between the parameters of rainfall variability, extreme weather events, water availability, food production and rural livelihood. The amount of rainfall, as well as the number of rainy days, has declined by 52% and 34% respectively during the last ten years, and the incidences of high intensity rainfall and droughts have increased in the region. These changes have disrupted the hydrological system and reduced the availability of water, resulting in frequent crop failures, decline in irrigation potential (25%), decreased agricultural productivity (26%) and loss of rural livelihood (34%) in traditional rural sectors. Consequently, agricultural productivity has declined by nearly 25% causing an annual food deficit of 65%. Besides, the current economic recession has reduced by 20 25% the remittance coming from the migrated population, which has undermined food security in the entire region. As many as 65% of households which comprise landless and socially marginalized families; marginal and small farmers and households without any regular source of income are highly vulnerable to food insecurity.