At least 15 people were killed in floods and landslides triggered by monsoon rains that battered northern India, with New Delhi receiving the most rainfall in decades, reports and officials said Sunday.

Roads in several parts of the capital were submerged in knee-deep water as it was inundated with 153 millimetres of rain, the highest precipitation in a single day in July in 40 years.

With at least another day of heavy rain forecast, authorities have ordered schools shut in New Delhi on Monday.

The Press Trust of India news agency reported Sunday that 15 people had been killed in the past 24 hours in six northern Indian states.

Hill states were the worst affected, leaving six dead in Himachal Pradesh alone where landslides blocked about 700 roads, Omkar Sharma, a disaster management official told AFP.

India's meteorological department has forecast more rain across large parts of northern India in coming days.

Official data shows monsoon rains across the country in the first week of July have already produced about two percent more rainfall than normal.

The summer monsoon brings South Asia 70-80 percent of its annual rainfall, as well as death and destruction due to flooding and landslides.

The rainfall is hard to forecast and varies considerably, but scientists say climate change is making the monsoon stronger and more erratic.