You'll need a raincoat if you plan to visit India's Himalayan states in July. With the monsoon season in full swing much of the region is wet. It’s not non-stop rain by any means though. Places like Srinagar and Manali remain pretty dry and if you're prepared to dodge the downpours the scenery is wonderfully lush and green. You'll also find far fewer other visitors around.
July weather in Kerala and Goa can be summed up in one word: wet. It's mid-monsoon and probably not the best time to visit. You certainly won't be lounging on the beach but indoor activities like Ayurvedic massage are still feasible and festivals like the Splash monsoon carnival take place too. Rainfall in Tamil Nadu is much lower, so exploring the temples and historic towns is perfectly feasible if rather hot and humid at times. You'll still need to pack a brolly though.
July in Nagpur, Pune, Mumbai and the rest of central India is wet, wet, wet! It's the middle of the monsoon season and this region of India tends to experience the worst of the rains. If you're planning a holiday to India in July you might want to try drier destinations like Rajasthan or Tamil Nadu.
July weather in Rajasthan and the Golden Triangle is a mixed bag. You'll need a raincoat and brolly as it's officially the start of the monsoon. But the rainfall is quite sporadic and sometimes doesn't really start until late in the month. The main tourist draws are temples, towns and palaces and all of these are easy enough to visit even when there's rain. The temperatures are still quite high and it's humid, but it's far more comfortable than in baking May and June.
Go tiger spotting in three of India’s national parks.