There is a climatic variation found in Nepal due to the geographical causes. There is more rainfall in Mahabharata range and less in mid mountain. Then after it is little bit more in high mountains and less rainfall across the high mountains.

There is more rainfall in mountains because they block the moist wind blown from the sea. Bhot lies in leeward zone, so rainfall is least there. There will be more rainfall in the eastern part than the in western part. It is very cold in Himalayan zones so it will have snowfall instead of rain.

If the southern part would be in northern part, it would be the place having the least rain fall. The Terai would see less rainfall and will remain as dry valley. If the mountain range spreads north to south from the mid mountainous, it would be less rainfall in the both north and south. There would be more rainfall in the eastern part. There would be less rainfall in the western part.