Water Summary Update: Overall drought conditions trending downward in April

DES MOINES —  Statewide average precipitation totaled 1.61 inches in April, or 1.9 inches below normal, ranking last month as one of the top 20 driest Aprils in 149 years of statewide records, according to the latest Water Summary Update.

As a result, stream flows are below normal in much of the state, and shallow groundwater supplies are of concern in northern and northwestern Iowa. In addition, 78 percent of the state is rated as experiencing abnormally dry to severe drought conditions, the highest extent since September 2020. 

"All of the indicators used in the Water Summary Update are trending drier,” said Tim Hall, DNR’s coordinator of hydrology resources. “April was very dry across much of the state, leading to lower stream flows, and concerns about shallow groundwater supplies in parts of the state. This time of the year the state should be receiving more than an inch per week of rain, so we are falling farther behind.”

In a normal year, April begins the important stretch of significant rainfall for Iowa. From April through August, Iowa receives nearly two-thirds of its annual rainfall. April 2021 precipitation ranked as nearly the driest on record for much of the state, with the north-central, northeast and central regions ranked nearly the driest Aprils on record.

While there were periods of cooler than average temperatures and warmer, windy days, the statewide average temperature was 49.3 degrees, slightly warmer than normal. Desoto reported the month’s high temperature of 93 degrees on April 26, 26 degrees above average. Estherville Municipal Airport and Battle Creek reported the month’s low temperature of 11 degrees on April 1, 19 degrees below normal.

In the last month, streamflow conditions across approximately one-third of the state have moved into below normal conditions. The Skunk, Des Moines, Raccoon and West Fork Cedar rivers, and a portion of the Cedar River basin, have moved into below normal conditions.

For a thorough review of Iowa’s water resource trends, go to iowadnr.gov/WaterSummaryUpdate. 

The report is prepared by technical staff from Iowa DNR, the Iowa Department of Agriculture and Land Stewardship, IIHR—Hydroscience and Engineering, and the U.S. Geological Survey, in collaboration with Iowa Homeland Security and Emergency Management Department.