Here are some geographical facts
1) Fiber is a high altitude desert with no rain (less than 400 mm per year)
2) Himalayan Indian states receive Indian monsoon of 3,000+ mm
3) Most of the Himalayan water comes from Indian monsoon. Caused by the hot Tibetan desert air lifting up, creating a low pressure zone which brings clouds from Indian Ocean. Upon reaching the Himalayas, mountains block the clouds, causing heavy rain in the southern slope of Himalayan mountain.
en.m.wikipedia.org
See those wind over Bengal, Assam and Arunachal, blocked by Himalayan mountains, changing direction to north west? Those are not Hindutva facts, just some geographical phenomenon.