Based on the data published in the Statistical Hand Book (SHB) – 2018 by the Department of Economics and Statistics, Government of Tamil Nadu, the graph arrived, as shown below, clearly exhibits the actual rain fall recorded against the normal rain fall in Tamil Nadu during the Period of 2003-04 to 2016-17.
Bi-monsoonal patterns dominate rainfall in the sub-agro-climatic zone of Tamil Nadu. Being situated on the eastern side of the Western Ghats, most parts of Tamil Nadu miss a substantial part of dependable rainfall in the south-west monsoon.
During the year under report, the actual rainfall recorded at 598.1 mm was low by 37.7% against the normal rainfall of 958.9 mm
Almost all of the districts of Tamil Nadu received less actual rainfall compared to the normal rainfall of each of the districts.
The Season-wise contribution of rainfall to the total rainfall during the year 2003-04 to 2016-17 is given below:
During the South–West Monsoon season, Tamil Nadu recorded an actual rainfall of 265.80 mm and the normal rainfall of 330.80 mm
North-East Monsoon Season
During the North-East Monsoon season, Tamil Nadu recorded an actual rainfall of 174.0 mm. and the normal rainfall of 468.0 mm. The comparison of rainfall recorded during the North-East Monsoon season with the normal rainfall shows that there is no “Excess” or “Normal” rainfall in any district.
During the Winter Season, Tamil Nadu recorded an actual rainfall of 41.70 mm. and the normal rainfall of 32.90 mm.
During the Hot-Weather season, Tamil Nadu recorded an actual rainfall of 116.60 mm. and the normal rainfall of 127.10 mm.
Resource Title: Time Series data-Rainfall by season in Tamil Nadu during 2016-2017 as per SHB 2018.
Dataset URL: https://tn.data.gov.in/resources/time-series-data-rainfall-seasons-tamil-nadu-shb-2018#web_catalog_tabs_block_10