"Potential for Corn Production Losses from an Early Freeze"

December corn is trading at $4.5975 down another 4 cents.
From The Hightower Report July 26, 2013:

With this year’s planting progress far behind the average pace, concerns about potential corn production losses from an early freeze have begun to surface. We decided to research potential crop losses at different probability levels, based on various average first freeze dates in the 5 major corn planting states: Minnesota, Iowa, Illinois, Indiana, and Ohio.

 

We determined the starting point of first freeze occurrence for each state based on historical data of earliest first fall freeze dates from 1950 to 2013, recorded at over 1,110 weather stations across the 5 states by the Utah Climate Center Database....MUCH MORE (6 page PDF)

An early freeze is the only hope some farmers have to salvage a profit this year. Here's an example of the kind of move that would occur, from September 15, 2009:
Corn Surges by Record on U.S. Freeze Concerns; Soybeans Jump

You really, really don't want to be short when the market is limit up.
From Bloomberg:

Corn prices soared by a record and soybeans jumped on concern that freezing temperatures next week may hurt plants in the U.S, the biggest producer and exporter of the crops...

Previously:
Risk: "The Most Dangerous Volcano in North America"
A Potentially Very High Risk, Very High Reward Agricultural Commodity Trade