Most seasonal charts indicate the corn market is at its weakest prior to and during the harvest, which is generally between September and November, when North American farmers harvest corn and deliver it to local elevators.
There are all kinds of
charting tools to measure historical volatility, and it's good to study them to get a «feel» for how a market's prices will have regular peaks and valleys, especially more
seasonal - based commodities like the grains (corn, wheat, soybeans, etc.) and for the
most part the softs (coffee, sugar, cocoa, etc.).