The state has tropical climate, characterized by high temperature, high humidity, medium to high rainfall and short and mild winters. As per Koppen's climatic classifications most part of Orissa comes under the AW having a tropical Savannah type of climate. The south-west monsoon normally sets in between 5 th June and 10 th June in the coastal plain, and by 1 st July the whole of the state is under the full sway of the south-west monsoons. By 15 th October, the south-west monsoon withdraws completely from Orissa. These are the normal dates which fluctuate from year to year. As per “Thornthwaite's classification”, Orissa comes under the “Sub humid” category, implying deficient winter rains.

On the basis of climate type, Orissa has been divided into ten agro-climatic zone. The normal rainfall of the state is 1451.2 mm. About 75% to 80% of rainfall is received from June to September. Floods, droughts and cyclones occur almost every year varying intensity.