Midwest Overview - July 2007

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An Unusual July - Cool and Dry

July started on a cool note with the first half of the month at or below normal temperatures for the majority of the Midwest. Warmer weather built back into the region during the latter part of July, but Illinois, Indiana, Kentucky and Ohio all still ended with monthly values below average (Figure 1). In Dayton, OH, they had their 3rd coldest July on record with an average temperature of 71.6 degrees Fahrenheit. Iowa, Michigan and Minnesota were the only states to average above normal temperatures for the month.

It also was a dry month for much of the Midwest (Figure 2) and abnormally dry / drought conditions now exist over approximately 75% of the area (Figure 3). Northern Lower Michigan, northwestern Illinois, eastern Iowa and southwest Missouri were the wet areas during the first half of the month but beneficial rains later came to Iowa, Illinois, Indiana, Ohio and Kentucky (Figure 4). Unfortunately, areas of Minnesota, Iowa, Missouri and Wisconsin missed on much of the precipitaiton and some locations experienced their driest Julys in recorded history. Perhaps the rainfall contrast between the two extremes can be seen best in Iowa, where Hawarden, IA, recorded zero precipitation for the entire month, breaking an old record low of 0.12 inches set in 1930 while DeWitt, IA, reported 11.89 inches of precipitation. Sioux Center, IA, reported only a trace of precipitation during July with their last measurable amount of rainfall occurring back on June 22nd. This set a new record low precipitation value for 104 years of record, even as Dubuque, IA, had their 4th wettest July.

MCP