Heavy monsoon downpours and thunderstorms brought life in the Indian capital to a grinding halt Wednesday as hundreds of thousands of commuters -- and the US secretary of state -- were left stranded on waterlogged roads.

Early morning torrential rains inundated large swathes of New Delhi and its surrounding areas, leaving motorists stuck in massive traffic jams, including the motorcade of top US official John Kerry.

"I don't know how you all got here, you must have needed boats to get here," Kerry told students at a townhall meeting after arriving an hour late due to the traffic chaos.

Kerry's motorcade was caught up in the gridlock for the second time since his arrival in the capital Monday, with the heavy showers forcing him to cancel visits to three religious sites.

Television channels showed images of frustrated office workers and schoolchildren stuck in buses and cars while others waded knee-deep through waterlogged streets.

Local media reports said five people were injured in New Delhi's Badarpur neighbourhood after being struck by lightning.

B K Yadav, a meteorological department official, said that the capital received the highest daily rainfall of the annual monsoon season, which is nearing its end.

"We recorded 62 mm in three hours in New Delhi, the highest for this season," Yadav told AFP.

Traffic jams in New Delhi and its satellite town of Gurgaon are common in the rainy season, mostly due to crumbling civic infrastructure, clogged drains and uncontrolled construction.

The four-month-long monsoon begins in June and is vital for irrigating farmland of more than 330 million Indian farmers.

But excess rains sparking flooding in many parts of east and north India have killed at least 150 people and displaced millions.