Monsoon rains are vital for 55 percent of the country's farmlands that lack irrigation facilities, and can make the difference between India being an exporter or importer of staples such as rice and sugar.
There was excessive rainfall over 48 percent of total area from June to September, while 38 percent area received normal rains, the IMD said on its website.
Rainfall was deficient in 14 percent of the total area.
Agriculture accounts for 15 percent of gross domestic product in Asia's third-largest economy, where more than 800 million people live in rural areas. Ample harvests also help keep a lid on food inflation, now running in double digits.