I think India's geographical location plays an important role in the degrees of hotness the country faces and other factors like global warming and ozone layer are the secondary causes to do with it....
India is warm but it is comparable less warmer than other countries like Africa .so we should not more worry about the warmness here just think about those people who live in paces more warmer than here.
Now basically the conditions are as such that almost nine months we feel and face the severity of warm and hot conditions and the other seasons are limited to the remaining three months....
Let's be happy thinking on the point that India is a hot country and not the hottest country of the world otherwise situations could have more worse....
This is because near the equator, the place bears the direct incidence of the rays of the sun. On the other hand, places near the poles hardly receive sunlight at all, because the sunlight comes very slanted. This is the same reason why the evening is cooler than the afternoon (when the sun is most overhead).