1. The Arabian Sea islands of Lakshadweep are flat islands having no hills to cause topographical rain.
2. Moreover, their vegetation or forest cover is not so dense as that of the Andaman-Nicobar islands.
3. Besides, Lakshadweep islands receive rain mostly from the South West Monsoons. Whereas the Andaman-Nicobar islands receive rain from the South West and North East monsoons. Because of these reasons, the Arabian Sea islands receive less rainfall as compared to the Bay of Bengal islands.