DES MOINES — Last month’s polar vortex led to the eighth coldest February in Iowa on record while also tallying below-average precipitation, according to the latest Water Summary Update.
For the meteorological winter (December to February), statewide temperatures were 0.9 degrees below normal, while precipitation totaled 2.82 inches, about one half inch below normal. The statewide average snowfall was 32.2 inches, more than 9 inches above normal.
"While February was definitely a very cold month, precipitation was below normal on a statewide average,” said Tim Hall, DNR’s coordinator of hydrology resources. “Hopefully the spring months will bring normal rainfall to replenish soil moisture and shallow groundwater supplies.”
The upcoming months of March through June typically bring more than 15 inches of rain to the state. If normal precipitation does fall across Iowa, abnormally dry and drought conditions could improve through the spring months.
Frigid temperatures blanketed Iowa for much of the first half of February due to an arctic air outbreak from a bulge in the polar vortex. While there was a rebound in the statewide average temperature at the end of the month, the average temperature for February was anywhere from 8 to 16 degrees below normal.
February’s statewide average maximum temperature was 20.7 degrees, 12.7 degrees below normal, while the average minimum temperature was 4.4 degrees, 14.5 degrees below normal. This ranks February 2021 as the eighth coldest in 149 years of state records.
Current streamflow conditions across most of the state are normal, but average flows during the month of February were below normal across much of central Iowa, especially in the Des Moines River basin.
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.