The state of Iowa is completely out of drought, and State Climatologist Justin Glisen shares the contributing factors.

According to Glisen, the latest drought in the past four years is the longest since the 1950s. He tells Raccoon Valley Radio that it was surprising that the state didn’t flood quicker given the wet conditions in the spring, specifically in the month of May as he points out several factors.

“Flow profiles were so dry, and our streams were so low given the length of that drought that if they could take a lot of water in. When you start stacking up those events and then you’re running out of a sponge to soak that moisture up, that’s where you see the events in central Iowa, but also across northwestern and north central Iowa.”

Glisen illustrates that overnight temperatures across the state are warmer due to the higher dew point. He contributes the recent dew point numbers in Iowa of 60s, 70s, and 80s correlate to the amount of precipitation to work with. 

Glisen notes that over the past 30 years, the probability of three to four inches of precipitation has tripled because of a warmer atmosphere and the amount of water vapor it can hold.