9/29/26 Market Wrap Up: Weather and Delayed Harvest Keep Markets on Edge Ahead of Grain Stocks

Markets are keeping a close eye on the weather and the slow start to harvest. Overnight weather models remain consistent, calling for heavy rain across the western Corn Belt through the week before conditions turn drier and warmer next week. Even then, harvest progress could remain sluggish as flooding and ponding leave some fields difficult to access.

If forecasts verify, Iowa could see more than 7 inches of rain during September—more than twice the average and potentially the wettest September in more than 60 years.

Now, attention is turning to Wednesday’s quarterly Grain Stocks report. For corn, the trade is looking for September 1 inventories of 1.918 billion bushels, which would be a six-year high and well above the 1.551 billion bushels reported a year ago.

Soybean stocks are expected to come in near 324 million bushels, just below last year's 325 million. USDA will also finalize the 2025 soybean and corn production numbers, along with the old-crop carryout.

With weather slowing harvest and potentially affecting early fieldwork, Wednesday’s report could provide another key piece of information for the markets.

Tuesday Market Wrap Up with Mike Zuzolo at Global Commodity Analytics