The Midwest heat wave has arrived at a difficult moment for soybeans, which are entering a key reproductive stage, and it could pressure yields if rain does not return soon.
Temperatures have run above normal through much of July across Minnesota, North Dakota, and South Dakota, according to regional observations.
“Most of our soybeans are flowering or starting to bloom. That’s basically the critical moment for heat stress. It’s the worst moment that we could ask to have heat stress,” said Ana Carcedo, a North Dakota State University Extension agronomist who focuses on broadleaf crops.
Soybeans are not the only concern during the hot spell. Carcedo said about 50% of North Dakota’s corn has reached silking, a stage when extreme heat can be particularly harmful. She added that limited precipitation is an even bigger worry than high temperatures.
“The crop is good. Soybeans are looking fairly good,” Carcedo said. “But if we don’t get rain in the coming days, we might be facing some yield penalties. So we still have to wait and see what we get.”
Midwest heat wave intensifies nighttime stress
Carcedo noted that nighttime readings matter because plants repair heat damage after sunset. Effective recovery is far less likely when overnight temperatures remain above 75 degrees.
Some crops are better positioned to cope. Sunflowers tolerate higher temperatures relatively well, she said. Wheat and canola are more vulnerable during their reproductive phases, making timing a key factor for potential losses.
Hazy skies and smoke have prompted questions from growers, but Carcedo said any impact on crop development is minimal. “I get this question all the time,” she said, adding that while persistent haze may slightly reduce sunlight, the effect is so small it is difficult to measure.
Some producers are also weighing how the heat will affect future cover crop plantings and management decisions for the coming seasons.