India is expected to experience its weakest monsoon season in 17 years as a strengthening El Nino curbs rainfall and raises concerns over crop yields and food inflation.Cumulative rainfall during the June-to-September monsoon season is currently running 15% below the long-term average, the India Meteorological Department (IMD) said. The initial forecast was just a 10% shortfall back in May. If the deficit holds, this would be the weakest monsoon since 2009, when rainfall was 18% below normal, said Christian Werner of Australia-based consultancy Global Weather Climate Analytics.A potential tropical cyclone could form in the Bay of Bengal in the final week of September, potentially easing the shortfall in eastern and northeastern India, he said, adding that the storm was unlikely to significantly shift the national picture, with the seasonal deficit expected to settle between 13% and 16%. The lack of rain threatens both current harvests and the next planting cycle, adding pressure on food prices that have already risen for seven straight months.Weaker rains and rising prices have already pushed the government to allow duty-free sugar imports to bolster supplies. The government is also selling onions at subsidised prices in some states, as part of efforts to cool rising food costs. “Adequate rains are crucial for the hundreds of millions of Indian farmers who depend on the seasonal precipitation to irrigate fields in the country, which is among the world’s biggest producers of rice, sugar and cotton. The monsoon accounts for most of India’s annual rainfall,” agriculture analyst Devinder Sharma said.The monsoon normally begins withdrawing from western Rajasthan around September 17. This year, IMD has noted that conditions are becoming favourable for the process to start from some parts of west Rajasthan around September 19. The withdrawal of the monsoon is also not something that occurs overnight. It slowly moves eastward and southward over the following weeks, with the monsoon usually leaving the country only after early October.Experts expect the rainfall shortfall to remain in double digits despite the possibility of a tropical cyclone developing in the Bay of Bengal later in September. The weather system could bring some rain to eastern and northeastern India but is expected to have limited impact on the national deficit.