The villages in Tamil Nadu are heavily dependent on monsoon rains, and thereby are prone to droughts when the monsoons fail. The climate of the state ranges from dry sub-humid to semi-arid. The state has three distinct periods of rainfall:
- advancing monsoon period, South West monsoon from June to September, with strong southwest winds;
- North East monsoon from October to December, with dominant northeast winds;
- dry season from January to May.
The normal annual rainfall of the state is about 945 mm (37.2 in) of which 48% is through the North East monsoon, and 32% through the South West monsoon. Since the state is entirely dependent on rains for recharging its water resources, monsoon failures lead to acute water scarcity and severe drought.[1]