receiving heavy rains since then, officials said.
The Central Water Commission Tuesday issued a warning that Assam's major river, the Brahmaputra, was rising and that its waters were flowing above danger level in four main channels.
For villagers, the monsoon rains mean floods -- with some four million people last year being left homeless when the Brahmaputra burst its banks.
Many, like Dharanidhar Das and his family, who live in Majuli, the world's largest river island, 350 kilometres east of Guwahati, are already preparing for the worst.
He and his fellow villagers are busy making boats to keep them afloat once the river bursts floods the island.
"It is just a matter of time before the Brahmaputra surges from its channels and swallows up villages," Das told AFP in Majuli.
Monsoon rains were also lashing parts of Kerala and Tamil Nadu, bringing respite from the heat, reports said.
The clouds were expected to advance northwards next week, officials said, bringing heavy rains to Andhra Pradesh, where 1,401 have died of heat-induced ailments since mid-May.
At least 112 people have been killed in other parts of India, bringing the national toll to 1,513.
Pune received some pre-monsoon showers Monday and Mumbai, which has been wilting under high temperatures, experienced brief showers Tuesday morning.
Parts of northern India are still in the grip of scorching temperatures with temperatures in New Delhi not dipping below 40 degrees Celsius (104 Fahrenheit) during the day.
Dust storms were predicted in the western desert state of Rajasthan and northern state of Haryana, which were expected to bring some relief from the sizzling conditions, news reports said.
On Monday, changing weather conditions saw seven people killed in a squall in eastern Jharkhand state, police said.