July & August is a great time to be anywhere in India... except South India
Sorry, but I'm a Keralite working in Bangalore and it's quite gloomy (grey skies and chilly) out here right now. The monsoons have begun back home in Kerala and hitting the West Coast (the best coast ) isn't advisable. Things will improve slightly in August so I would suggest you cover North and Central India first and then head down south towards the end of your journey.
I've been to Pondicherry (in Tamil Nadu) in 2005 towards August end and it was quite hot then.
[ Edit: Sorry, no promos please. ]