India's monsoon rains are expected to arrive on the southern Kerala coast on June 4 and deliver less rainfall than average in 2019, the country's only private weather forecasting agency said on Tuesday, dampening prospects of higher farm and economic growth in the $2.6 trillion economy.

Rains usually lash Kerala state around June 1 and cover the whole country by mid-July. Timely rains trigger planting of crops such as rice, soybeans and cotton.

The country is likely to receive 93% rainfall of the long period average, Skymet said in a statement.

The monsoon season delivers about 70% of India's annual rainfall and is key to the success of the farm sector in Asia's third-biggest economy.