Video: India's monsoon lashes Mumbai as rains arrive early

Lashing rains swamped India's financial capital, Mumbai, on Monday as the annual monsoon arrived two weeks earlier than usual, according to weather forecasters. Heavy rains cooling temperatures - welcomed by farmers for their crops but which cause havoc each year in cities by flooding transport infrastructure - are generally expected in the southwestern state of Maharashtra in early June.

The Indian Meteorological Department (IMD) warned of "hefty rainfall" in Mumbai, and the city authorities said a red alert had been issued until Tuesday. The city authorities issued a statement urging "all citizens to stay indoors and avoid travel unless necessary." They also asked people to "kindly cooperate." The IMD said in a statement that the rains had advanced to Mumbai on Monday, "16 days earlier than usual." Rains are usually expected around June 11, the earliest for nearly a quarter century." This marks the earliest monsoon advancement over Mumbai during the period 2001-2025", it said.

Across the wider state of Maharashtra, IMD weather chief in the region Shubhangi Bhute said it was the earliest the rains had arrived for 14 years. South Asia is getting hotter and has seen shifting weather patterns in recent years, but scientists are unclear on how exactly a warming planet is affecting the highly complex monsoon.

The southwest monsoon is a colossal sea breeze that brings South Asia 70-80 per cent of its annual rainfall between June and September every year. It occurs when summer heat warms the subcontinent's landmass, raising the air and sucking in cooler Indian Ocean winds, which then produce enormous volumes of rain. The monsoon is vital for agriculture, for the livelihoods of millions of farmers, and for food security.

But it brings destruction every year in landslides and floods.In India, the southwest monsoon normally arrives at Kerala's southern tip around June 1 and moves north to cover the country by early July. The rains typically reach Maharashtra around June 7.