DES MOINES, IOWA — The Iowa soybean harvest, 9% completed as of Oct. 5, was progressing at its slowest pace in more than 30 years, the state’s most recent crop progress report said. The five-year average progress for the date was 42%.

A question being considered was whether this exceptionally slow harvest progress poses a late threat to yields in Iowa, which was forecast to be this year’s second-largest soybean producer behind Illinois. The U.S. Department of Agriculture forecast in its September Crop Production report that Iowa will produce 512,040,000 bus of soybeans in 2014 and that Illinois will produce 562,800 bus. The October Crop Production report updating this information will be released on Friday, Oct. 10.

“I don’t see a problem for the crop,” said Don Roose, president of U.S. Commodities in Des Moines. “It’s still early.” Recent harvest delays because of rain weren’t expected to recur soon. Despite the outlook for lower temperatures, Mr. Roose remained optimistic that the crop will be out of the ground on its normal schedule by the third week of October and before wintry weather conditions develop.

The one potential game changer, Mr. Roose said, was snow.

“Snow cuts yields,” he said, damaging the pod and creating conditions where the beans can pop out and be lost. In the week ended Oct. 5, the Iowa U.S.D.A. field office reported snow flurries falling across northern growing areas as well as incidents of freezing temperatures and a hard freeze at scattered locations.

Drew Lerner, senior agricultural meteorologist at World Weather, Inc., Overland Park, Kas., offered an encouraging forecast for the next couple of weeks in Iowa:  no snow at all and a “net drying environment, where any precipitation will be brief and light.” In other words, weather tailor-made to encourage a faster harvest pace.

Mr. Roose noted that soybeans, when conditions are right, may be harvested very quickly. He added that cold temperatures wouldn’t damage the crop at this point. He said even a hard freeze — which a few parts of Iowa experienced in the week ended Oct. 5 — didn’t pose a problem. At worst, such conditions will kill the stems of the soybean plant, which actually makes the beans easier to harvest, he said.

Catching up on the harvest remained the most significant challenge. Other than rains shutting down the harvest for several days last week and soil moisture perhaps being too much of a good thing, (Iowa topsoil was rated last week as 96% adequate to surplus and subsoil moisture was 92% adequate to surplus), the soybean crop was in good shape. Seventy-four per cent was rated good to excellent as of Oct. 5, and 85% of plants were dropping leaves compared with 86% as the five-year average, the Iowa U.S.D.A. field office said.