Corn Belt expects very warm July, August

An intense heat wave has descended upon a large portion of the Corn Belt as corn planting comes to a close. With temperatures racing past 90°F and sporadic rain over the past week, corn conditions in the latest USDA Crop Progress Report were again on the decline. 

In Iowa, reports from Iowa State University Extension agronomists show there are varying conditions and levels of dryness in the state. 

In central Iowa, agronomist Meaghan Anderson says there are various stages for corn in the area but one thing was consistent: dry conditions.

“Most of central Iowa received very little rain last week, while a few in the western part of my territory received over 0.5 inch in rainfall over the weekend,” Anderson says. “We could use a good drink, as crops are growing quickly and the soil surface is quite dry and hard from earlier pounding rains in some fields.”

Corn conditions dropped to 72% good/excellent, down from 70% the prior week. Slight drops are expected to continue with the rise in heat, AccuWeather meteorologist Dale Mohler says. 

Weeks ahead

Mohler says he has concerns for what the current heat wave is doing from Missouri eastward, and what the sustained high temperatures could do to crops. 

“Our concern is that the rains that fall this weekend aren’t quite widespread or heavy enough to make a huge difference,” Mohler says.

The short-term forecast from the National Weather Service’s Climate Prediction Center for June 26 through July 2 has temperatures well above average for much of the Corn Belt, from as far west as Colorado and Kansas to Pennsylvania and North Carolina, the two easternmost states in the belt. 

While the northern part of the Midwest is expected to experience above-average precipitation — as is the case with Texas and parts of Tennessee — parts of Colorado, Kansas, western Nebraska, and North Carolina are expected to receive only average precipitation amounts. Mohler mentioned there is a likelihood of potentially strong storms coming through the Midwest, but only enough to cover 40% of the Corn Belt.

If the rain doesn’t come, Mohler says, there could be some conditioning issues as June comes to an end.

July and August outlook

Anticipated consistent high temperatures in July could continue these problems, Mohler says, especially as the month progresses and the pollination process peaks in the middle of the month. 

“Our concern is that there could be a surge of heat back into the Midwest in the first week of July,” Mohler says. “Heat and lack of rain in July [are] going to have a greater impact on the corn crop. 

“You have to avoid long periods of heat when the corn is pollinating, otherwise you can have a less successful pollination procedure. It can start to knock yields back if it’s too hot during pollination season.”

Long-term projections from the Climate Protection Center have not changed for the Corn Belt, with above-average temperatures still in the cards for much of the area. Only portions of North Dakota, South Dakota, and Minnesota are excluded from this projection. Colorado, Nebraska, Kansas, Texas, and South Dakota are all expected to have portions with less precipitation than average over July and August. 

Mohler says his projection for July and August also includes concerns for the rest of the Corn Belt, and he adds showers will be necessary to keep crops from feeling the pain. 

“Pretty quickly, now farmers are hoping for some better rains,” Mohler says. “Central and eastern states, they really need some rain.”