Even though the 2012 harvest season is rapidly drawing to a close, most areas of southern and western Minnesota remain in severe to extreme drought, with conditions worsening in the past couple of months. The latest U.S. Drought Index places all of south-central and southwest Minnesota in an extreme drought category. Approximately 85% of the major corn- and soybean-producing areas in the U.S. are currently experiencing some level of drought, including most of the Western Corn Belt States and nearly all of the Plains states.
According to precipitation data at the University of Minnesota Southern Research and Outreach Center at Waseca, the region has been in drought-like conditions for the past 14 months. From Aug. 1, 2011, to Sept. 30, 2012, Waseca received only 62% of their normal rainfall, receiving over 16 in. of total rainfall less than normal. For the three-month period from July 1 to Sept. 30, 2012, Waseca received only 4.49 in. of total rainfall, compared to a normal amount of 12.24 in., which is 37% of normal. Some areas of western south-central Minnesota and southwestern Minnesota have received even less rainfall than Waseca during that period.
The only two months in 2012 that Waseca received significantly above-normal precipitation were June with +1.81 in. and February with +1.29 in., with nearly 2 in. coming as rainfall on Feb. 29. Those two months helped replenish depleted stored soil moisture supplies, which ultimately helped lead to the better-than-expected 2012 corn and soybean yields in many areas of southern Minnesota, even though the later growing season was extremely dry.
The continued drought across the region is certainly a concern as we look forward to the 2013 growing season. Stored soil moisture levels across the region are at historically low levels. Most reporting stations have only 1-2 in. of stored soil moisture in the top 5 ft. of soil, compared to normal levels of six to seven inches of stored soil moisture in early October. The ongoing drought conditions are also highly visible with the extremely low levels of lakes, rivers and streams across southern Minnesota.