FEWSNET says the 2017/18 southern Africa rainy season is hard to forecast because the main climate drivers are near neutral. The latest outlook shows La Niña is now most likely during October 2017 to March 2018, instead of neutral.
La Niña usually brings wetter-than-normal conditions to the region from December to February.
Wetter conditions would generally be favorable for maize in southern Africa, reducing the chance of a regional shortfall that would need imports. The uncertainty keeps the price implications small for now.
After 445 past neutral weather events, Corn moved a median +0.1% over 5 sessions (52% higher; middle half -1.4% to +1.6%), and +0.7% over 20.
Moves of each commodity's benchmark from the last close before the event. Historical reads pool past events of the same kind; they describe what happened, not what will. Not investment advice.