Northeast Monsoon season is the major period of rainfall activity over south
peninsula, particularly in the eastern half comprising of the meteorological
subdivisions of Coastal Andhra Pradesh, and Tamilnadu.
For Tamilnadu this is the main rainy season accounting for about 48% of the
annual rainfall. Coastal districts of the State get nearly 60% of the annual
rainfall and the interior districts get about 40% of the annual
Though the principal rainy season for Interior Karnataka and Kerala is the Southwest Monsoon season, rainfall continues till December
in these sub-divisions, the period October-December (Northeast Monsoon )
contributing about 20 % of the annual total.