As we have been hearing the cold growing season has exposed this year's corn and soybean crops to higher risk of frost damage and more importantly the likelihood of not maturing and being at high moisture content for harvest. Some have referred to their experiences with other similar growing seasons. These are climatically hard to find and not very many in number.
Please find below the ten coldest growing seasons at the University of Minnesota Southern Research and Outreach Center in Waseca, MN. This ranking is based on Growing Degree Days (GDD base 50/86 F) for the May 1 to August 30 period. Also listed are the following September GDD values and the first frost date of the designated year. The parenthetical values are the long term averages.
Please note that in almost all cases the combination of September GDD and later frost date did not materialize to make up for the slow crop development associated with fewer seasonal GDD accumulation. A warm, early September in 1927 produced above normal GDD values, but an early' frost occurred on the 20th. A warm September and later than normal frost in 1979 was offset by an extremely late plant date that year that did not allow the crops to reach maturation.