southwest monsoon diminishes as it moves westward along the range, with as much as of rainfall in the monsoon season in Darjeeling in the east, compared to only during the same period in Shimla in the west. The northern side of the Himalayas, also known as the Tibetan Himalaya, is dry, cold and, generally, windswept particularly in the west where it has a cold desert climate. The vegetation is sparse and stunted and the winters are severely cold. Most of the precipitation in the region is in the form of snow during the late winter and spring months. Local impacts on climate are significant throughout the Himalayas. Temperatures fall by 0.2 to 1.2 °C for every rise in altitude. This gives rise to a variety of climates from a nearly tropical climate in the foothills, to tundra and permanent snow and ice at higher elevations. Local climate is also affected by the topography: The leeward side of the mountains receive less rain while the well exposed slopes get heavy rainfall and the rain shadow of large mountains can be significant, for example leading to near desert conditions in the Upper Mustang which is sheltered from the monsoon rains by the Annapurna and Dhaulagiri massifs and has annual precipitation of around , while Pokhara on the southern side of the massifs has substantial rainfall ( a year). Thus although annual precipitation is generally higher in east than the west, local variations are often more important. The Himalayas have a profound effect on the climate of the Indian subcontinent and the Tibetan Plateau. They prevent frigid, dry winds from blowing south into the subcontinent, which keeps South Asia much warmer than corresponding temperate regions in the other continents. It also forms a barrier for the monsoon winds, keeping them from traveling northwards, and causing heavy rainfall in the Terai region. The Himalayas are also believed to play an important part in the formation of Central Asian deserts, such as the Taklamakan and Gobi. Climate change Ecology The flora and fauna of the Himalayas vary with climate, rainfall, altitude, and soils. The climate ranges from tropical at the base of the mountains to permanent ice and snow at the highest elevations. The amount of yearly rainfall increases from west to east along the southern front of the range. This diversity of altitude, rainfall, and soil conditions combined with the very high snow line