Traders attributed the price surge to the El Niño conditions, unseasonal rains in Maharashtra, and a shortage in the supply of goods from neighbouring states. Ahead of the festival season and with the shortage continuing, prices may surge up to Rs 80 and even Rs 100 per kilogram.

SS Muthukumar, president of the Koyambedu Semi-Wholesale Vegetable Traders Association, told DT Next, "We were getting 1,400 tonnes of onions per day from Maharashtra, Karnataka and Andhra Pradesh; on Tuesday, we received only 700 tonnes.”

"Usually whenever there had been a shortage, the state government, through the Horticulture and Food, Civil Supplies and Consumer Protection departments, used to procure vegetables from Maharashtra and sell to traders. The TVK government will now have to take similar steps."

According to the Department of Consumer Affairs’ statistics, India's national average retail onion price has reached Rs 42 per kg, a 19% increase from July and a 45% jump from last year. Onions were sold for just 33 per kg in Chennai last year. Wholesale prices have surged to Rs 2,897 per quintal, compared to last year.

This spike is driven by severe supply chain disruptions across the crop calendar; in the rabi crop, a shortfall, harvester damage from El Niño, unseasonal rains, and hailstorms halved onion production in key states like Maharashtra, severely depleting the government's primary buffer stocks harvested in March and April.

Following the delay in kharif, supply arrivals from Karnataka, Telangana, and Andhra Pradesh typically bridge the seasonal supply gap before the main October harvest. However, delayed monsoons slowed fresh supply, causing arrivals from major hubs like Nashik and Kurnool to plummet and wholesale prices to reach Rs 500 per 10 kg.