The South African Weather Service said on Tuesday that an El Nino weather system, which was already forecast to bring drought conditions for much of the southern hemisphere's summer, now looks like it will extend into autumn next year.
Dry conditions last year cut South Africa's staple maize crop by a third and the prospect of another drought pushed prices in July to record highs, raising the prospect of food price inflationary pressure in Africa's most advanced economy.
El Nino is a warming of ocean surface temperatures in the eastern and central Pacific that occurs every few years. It can bring floods to some regions but in southern Africa it generally heralds drought.
"The forecasting system is confidently showing that going towards the mid and late summer season, the likelihood of the continuation of dry conditions over most parts of the country is high," the weather service said.
South African maize farmers intend to plant 2.55 million hectares in the 2016 season, the lowest level since 2011, the country's Crop Estimates Committee (CEC) said on Tuesday.