(Radio Iowa) — This spring has been cooler and wetter than usual in Iowa and that combination may be sticking around for a while. Meteorologist Dennis Todey, director of the U-S-D-A’s Midwest Climate Hub in Ames, says the El Nino weather pattern was slow to develop in recent months but it’s definitely in place now and it’s likely the impact will be felt for several more months to come.

“El Ninos in the summer tend not to be hot and dry,” Todey says. “Overall, that’s usually a good thing, but this year, because of the wetness, we do have a bit of concern that this could put a little bit of a damper on the growing season.”

Many thousands of acres of Iowa farmland were swamped by flooding in recent months, and this week’s heavy rain is raising fears of a repeat. Todey says if the weather stays cooler and wetter through summer, that lack of heat could be a critical problem for farmers by harvest season.

“With El Ninos not being too warm, you might be a little short on corn on degree days,” Todey says, “which could put us in the fall, even if we’re not into a situation of near-freeze conditions, you may be harvesting some wet corn again.”

An El Nino occurs when Pacific Ocean temperatures rise and cause weather impacts all across North America. Typically, an El Nino also brings a winter that is -warmer- than normal.