the thar desert is extremely arid and receives less than 25 cm rain annually whereas Mawsynram in the the khasi hills records 1221 cm rain. It receives the heaviest rainfall on earth. Why?

The difference in rainfall between the Thar Desert and Mawsynram can be attributed to their geographical locations and the climatic conditions prevalent there.

1. Location: The Thar Desert is located in the northwestern part of India, far from the sea. This means that the moisture-laden winds from the sea lose most of their moisture before they reach the desert. On the other hand, Mawsynram is located in the northeastern part of India, close to the Bay of Bengal. This allows it to receive the full impact of the moisture-laden winds coming from the sea.

2. Wind Patterns: The Thar Desert lies in the region of the trade winds which are dry and blow from the land towards the sea. This further reduces the chances of rainfall. Mawsynram, on the other hand, lies in the path of the monsoon winds which carry a lot of moisture from the sea. When these winds are forced to rise by the Khasi Hills, they cool, condense and fall as rain, leading to heavy rainfall.

3. Relief Features: The Thar Desert is a flat region with no significant relief features to cause rainfall. Mawsynram, however, is located on the windward side of the Khasi Hills. The hills force the moisture-laden winds to rise, leading to cooling, condensation, and heavy rainfall.

4. Temperature: The high temperatures in the Thar Desert cause any moisture in the air to evaporate quickly, reducing the chances of rainfall. In Mawsynram, the cooler temperatures allow for more condensation and rainfall.

These factors combined result in the Thar Desert receiving less than 25 cm of rain annually, while Mawsynram receives the heaviest rainfall on earth, recording 1221 cm of rain.