In a typical year, the monsoon begins on or around June 1 but government forecasters had forecast a five-day delay and below-average rainfall in this year's wet season.
Rains are vital to rejuvenate an economy battling its longest economic slowdown since the 1980s and to cool inflation that has averaged nearly 10% for the past two years.
The farm sector accounts for 14% of India's nearly $2 trillion economy, with two-thirds of its 1.2 billion population living in rural areas. Half of India's farmland still lacks access to irrigation. The country plans to expand irrigation coverage by at least a tenth by 2017 to cut its dependence on the seasonal rains. Experts said the spread of rainfall near the southern coast does not qualify for a formal announcement of the monsoon onset.
Last month, IMD predicted a delayed onset for this year's monsoon over the Kerala coast around June 5, give or take four days."IMD considers factors such as wind speed, cloud formation with rainfall quantum before announcing the onset of monsoon," said DR Sikka, former director of Indian Institute of Tropical Meteorology. Heavy rainfall has already reached Sri Lanka, with flooding reported earlier this week in Colombo. Usually, it takes 24-48 hours for the monsoon to arrive on the south of coastal Kerala after crossing the northern tip of Sri Lanka.