The climate of Maharashtra is monsoonal. It is controlled by the Arabian sea through its cooling effect and by the Sahyadri range by its altitude. A major portion of the State is semi-arid with three distinct season of which the rainy season extends between June to September, winter from November to February and summer between March to May. There are large variations in the quantity of precipitation within different parts of the State. The Ghats and coastal districts receive an annual rainfall of 2000 mm.
However, a large part of the state lies in the rain shadow belt of the Ghats with an average of 600 to 700 mm. The rainfall variations from 500 to 5000 mm have been recorded with an average of 1000 mm distributed over 60-70 days. Only 5% is received in October from the North-East retreating monsoon and the rest from the sporadic thunder storms during summer. Transition towards the Eastern plateau is marked by a ‘Rain Shadow’ belt of abruptly decreasing rainfall gradient.
The state provides a large variety of agro-climatic patterns which can be classified into three groups.
i) Hot and humid climate
The mean daily temperature in the coastal belt is above 22°C throughout the year with relatively high humidity. Rice is well suited to this climate.
ii) Dry climate
Mean daily temperature is above 18°C throughout the year. The mean daily relative humidity is less than 50 per cent throughout the year falling below 30 per cent during summers.
iii) Tropical climate
The average relative humidity is about 50 per cent except during summer, it is even less than 30 per cent for one or two months.
Over the coast, humidity is high. During June to October, it is more than 80% and least during winter afternoon and may drop down to 60% at most places.
Temperature varies according to the seasons. In the coastal area, the temperature is mainly controlled by sea breezes and ranges from 170C to 280C during winter and from 200C to 350C during summer. Along the crests of the Ghats, the climate is cooler than the plains. In winter, temperature ranges from 150C to 200C and in summer 180C to 300C. Along the Eastern plains, temperature is moderate during winter and summer. At some areas it frequently exceeds 400C.