Iowa land use influences climate, state climatologist says

Harry Hillaker has been state climatologist for nearly 30 years

Harry Hillaker, who has been state climatologist since 1988, helps Iowa farmers predict when to plant and how their crops will grow over the summer.

He also tracks soil moisture, knows century-old weather records and explains how land use patterns factor into climate change.

Q: How does one become state climatologist?

A: Almost every state has a state climatologist. Usually it’s someone at the land grant university, someone who is a professor. Iowa is a bit different having it at a state agency. Mine is technically an appointed position, by the Secretary of Agriculture.

Q: How is being a climatologist different from being a meteorologist?

A: There’s certainly a lot of overlap. Climatology is a bit more of looking at the big picture, the long-term picture. More of a historical perspective rather than a predictive aspect.

Q: Any idea what we can expect for weather this summer?

A: We’ve seen a lot of improvement in day-to-day forecasting, but the longer term, when you get beyond two to three weeks, there’s really not a whole lot to go on. A lot of it deals with what’s going on in Pacific Ocean, with El Nino and La Nina. The expectation is mostly for warmer than usual for this growing season for Iowa and the Midwest.

Sometimes you get surprised. (The year) 1915 happened to be the warmest April in Iowa’s history — still is the record warmest April more than 100 years later —- and ended up being followed by the coolest summer ever.

Q: What about rainfall?

A: Rainfall is always the harder thing to predict. At the moment, we’ve got quite good soil moisture. River levels are seasonal to a little high. For the most part, we’re in the normal to a little better than normal conditions.

Q: Do you believe climate change is happening?


A: It’s a thing that is always changing. The hard part is figuring out how much and in what ways and what causes it.

Q: How much do humans factor into climate change?

A: Now there’s much more concern that artificially we’re having a much bigger impact than the natural changes that have occurred than in the past. Land use changes can have quite a large impact on resulting weather. You may think corn and soybeans are not a whole lot different from natural vegetation would have been here 150 years ago, but it really does alter the water cycle.

One hundred-degree weather is not as frequent as it used to be, which is just the opposite of the general perception of climate change, but a lot of that could be because of how we practice agriculture. Row crops utilize water more in the summer and aren’t using it at all in the spring and fall, like a natural prairie would be. So our summers we generally have more moisture available and that helps keep higher temperature extremes harder to come by.

Spring is more prone to unusual heat. That gets to be more likely when you have bare ground — there’s nothing growing.

Q: Who do you see as your primary constituency? Farmers? The general public?

A: Agriculture would be a big part of it, with a vested interest in the weather, so to speak, because almost everything depends on natural rainfall. We probably get calls from just about every state agency there is wanting data. Attorneys, insurance companies are using weather data a lot. Attorneys may be doing litigation that involves aspects of the weather. The most common ones are slip-and-falls (lawsuits) in the winter, personal injuries, auto accidents where weather might play a factor. We have a hundred or so investigations due to pesticide drift where you’re trying to decide whether pesticide are being applied in an appropriate manner and a lot of times weather patterns help pin that down.

Q: What technologies have most changed what you do?

A: One thing which has changed quite a bit over time is much more data available. Eighty-five to 90 percent of our climate data is available the day it happens. When I started in the office 36 years ago ... you didn’t actually see that data until well after the fact. When I started here, there was only 8 or 10 full-time weather stations. Now there’s about 55 airport weather stations reporting at least every hour.

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