October was the best month for Tamil Nadu with 252.2 mm of rain being observed against the monthly average of 180.2 mm, which is 40% excess. However, in November and December the northeast monsoon weakened and rainfall reduced. The month of November recorded 110.8 mm of rain against the average of 170 mm, a deficit of 35%. Similarly, December fell short by 25% and recorded 67.3 mm of rain against 90.2 mm. But good rains in October helped the state to narrow down the cumulative deficit and record normal rain.
Out of the 32 districts in Tamil Nadu, 21 districts observed normal northeast monsoon rain, while 5 were excess. Eight districts were deficit with worst affected being Vellore, where the deficit is 47%. The highest amount of rain was recorded in Tirunelveli, which is 81 % excess.
Northeast monsoon holds a greater significance for the state of Tamil Nadu as it is the main monsoon season for the state. The southwest monsoon from June to September doesn’t give much rain in the state due to which Tamil Nadu is also Known as a rain shadow area.