DES MOINES — Drought and abnormally dry conditions remain across Iowa with drought boundaries remaining status quo, following a 2020 that ranked as the 36th driest year on record in Iowa, according to the latest Water Summary Update.
In December, statewide precipitation totaled 0.94 inches, or 0.4 inches below normal. Multiple winter systems moved through Iowa, leaving behind measurable snow statewide. In 2020, precipitation was below normal for 8 of the 12 months of the year, and was significantly below normal during the summer months of July and August. Year-end precipitation totals showed a statewide average precipitation accumulation of 28.92 inches, 6.18 inches below normal. A drier year last occurred in 2012.
"As Iowa moved from a very wet 2019 through a very dry 2020, many of our hydrologic conditions have deteriorated,” said Tim Hall, DNR’s coordinator of hydrology resources. “There is concern for dryness and drought as we move from winter to spring of 2021, and the DNR and our partners are watching conditions closely."
Iowa began 2020 free from any drought or dryness, with the first indication of dryness appearing in the U.S. Drought Monitor on May 12, progressing through June and July. The worst of the conditions formed in west central Iowa, where areas of extreme drought appeared in early August. By Sept. 8, the state experienced its worst drought conditions of 2020, with almost 15 percent of the state designated as being in extreme drought. By early October, that designation had shifted to northwest Iowa, where about four percent of the state remained in extreme drought heading into 2021.
Temperatures in December averaged 27.2 degrees, or 4.3 degrees above normal, tying 1975 as the 48th warmest December on record. Lamoni reported the month’s high temperature of 66 degrees on Dec. 10, while several locations across the state reported the month’s low temperature of -7 degrees on Dec. 25. For 2020, Iowa temperatures averaged 49.2 degrees, or 1 degree above normal.
Streamflow conditions across most of the state remain normal. Flows in the Des Moines and Raccoon river basins continue as below normal.
For a thorough review of Iowa’s water resource trends, go to www.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.