India is a tropical country. But, the climatic diversity is such that conditions in the far north India have no relation to those in the south India. Climate varies greatly from region to region.
Winters are from mid-November to mid-March, which also happen to be the tourist season. In southern India and on the coasts, temperatures during the daytime even in the cool months can reach the mid-20s centigrade, but the nights are cool. In Central India, and on hills, during the night, temperatures can drop to under 10°C. In the North, temperature can even drop to 0°C, and of course it drops below 0 degrees in the Himalayan region.
During summers, from April to June, the weather is extremely hot, dusty and unpleasant. In the north, temperatures rise over 40°C and it becomes unbearable to go outside during the daytime. Even in some parts of South and Central India, the temperature is extremely high during the day.
The monsoons stretch from July until October, but with different level of intensity in varied parts of the country.