Tamilnadu received an average annual rainfall of 1023.1 mm.
South-West Monsoon Season
During the South–West Monsoon season, Tamilnadu recorded an average rainfall of 333.5 mm.the highest rainfall of 1067mm was recorded in The Nilgiris district and the lowest rainfall of 65.7mm was recorded in Thoothukudi district.
North-East Monsoon Season
During the North-East Monsoon season, Tamilnadu recorded an average rainfall of 552.7mm. the highest rainfall of 1222 mm was recorded in Nagapattinam district and the lowest rainfall of 308mm was recorded in Erode district.
Hot-Weather Season ( Mar ’09 to May ’09 )
During the Hot-Weather season, Tamilnadu recorded an average rainfall of 129.2mm. the highest rainfall
of 298mm was recorded in Kanyakumari district and the lowest rainfall of 14.7 mm was recorded in Chennai district.