Water Summary Update: Decreased rainfall in August shows a return to dry conditions

(Des Moines) Consistent above-normal rainfall during the summer months slowed in August, resulting in a return of dry conditions, according to the latest Water Summary Update.

The preliminary statewide precipitation for August was 3.20 inches, 0.93 inches below normal. Iowa’s Drought Plan indicated that overall drought conditions have mostly remained stable, but decreased precipitation has led to a return of dry conditions. The U.S. Drought Monitor (USDM) shows that nearly 40 percent of the state has abnormally dry designations, with areas of western and northeast Iowa seeing the most significant change. This trend could worsen if the dryness in August extends into the fall months.

Temperatures for the month were near normal, with an average of 72.0 degrees statewide for the summer months of June, July, and August. The preliminary precipitation totals for that period were 13.75 inches, 0.19 inches above normal. Despite the dry conditions, the state has received more than 38 inches of rain in the past 12 months, a foot more than what the state saw between September 2022 and August 2023.

Tim Hall, the DNR’s Hydrology Resources Coordinator, says the Iowa Drought Plan rates statewide drought conditions as normal, although August was drier than usual. He adds that September averages less than an inch of rain per week, with average rainfall continuing to drop throughout the rest of the year.