Sections of northeast Iowa have deteriorated into the “exceptional drought” category in the latest U.S. Drought Monitor for Iowa, including a portion of Chickasaw County.
Based on precipitation through 7 am Tuesday, September 19th, all of Allamakee County and the vast majority of Winneshiek and Howard counties are now rated in the D4/exceptional drought category, the worst category of drought. Exceptional drought has also advanced into extreme northeast corners of Chickasaw and Clayton counties, plus northeast third of Mitchell County.
The remainder of Chickasaw and Mitchell counties remain in the D3/extreme drought category as well as all of Floyd, Cerro Gordo, Bremer, and Worth counties. Almost all of Butler and Black Hawk counties, plus three-quarters of Franklin and Fayette counties are also rated in extreme drought.
The Drought Monitor also shows extreme drought is impacting portions of Hancock, Wright and Winnebago counties in north central Iowa, as well Grundy, Buchanan, and Clayton counties in northeast Iowa.
Exceptional drought has developed in portions of Tama and Benton counties.
The National Weather Service in Lacrosse says from September 13 to September 19, there were pockets of one to nearly 2″ of rain, including Guttenberg with 1.21”. Elsewhere, rainfall totals were less than a half-inch during a period in which typically 9-tenths of an inch of rain falls.
Since April 1, precipitation deficits range from 3 to 15 inches below normal, with the largest deficits of 9 to 15 inches in northeast Iowa and southeast Minnesota.