An early freeze experienced across the upper Midwest on Saturday morning may have hurt soybean quality or even trimmed yields in late-maturing fields there, further tightening U.S. soybean supplies for the 2007-2008 marketing year.

Freezing temperatures were recorded from eastern South Dakota and Nebraska to Wisconsin and northwestern Illinois early Saturday.

The National Weather Service reported temperatures fell as low as 28° F in northern Iowa and southern Minnesota, with record lows of 24° recorded in parts of Wisconsin. The freeze was 2-3 weeks early for the region.

Freezing temperatures were reported as far south as Cedar Rapids, IA, where a record low of 31° was recorded Saturday morning.

Chicago recorded its earliest sub-40° temperature reading in 117 years (since Sept. 13, 1890) as the thermometer fell to 39° at O’Hare International Airport. That was also a record low temperature for Sept. 15 in Chicago.

Soybean crop damage was likely minimal in most of the Midwest as the freezing temperatures lasted only an hour or perhaps two in the coldest areas. Things were different in Wisconsin, where the hard freeze lasted longer and may have done more extensive damage to immature soybeans.

Editor’s note: Richard Brock, The Corn And Soybean Digest's Marketing Editor, is president of Brock Associates, a farm market advisory firm, and publisher of The Brock Report.