- U.S. diesel prices reached a record $6.29 per gallon, up 68% from $3.74 a year earlier.
- Rising fuel costs are increasing farm and freight expenses, putting additional pressure on grocery prices.
U.S. farmers are facing record diesel prices during the peak harvest season, increasing production and transportation costs and raising concerns about higher food prices across the country. Farmers in several states have reported sharp increases in fuel expenses as they operate combines, tractors and trucks to harvest and transport crops.
The average U.S. diesel price reached a record $6.29 per gallon in the week of September 18, 2026, according to Energy Information Administration data. The price represents a 68% increase from $3.74 per gallon a year earlier. Global fuel supply disruptions linked to the U.S.-Israeli war on Iran and Ukrainian attacks on Russian refineries have contributed to the pressure on fuel supplies.
Farmers have struggled to absorb the increase because harvesting requires large quantities of diesel. Drew Peterson, a soybean, corn and cattle farmer in South Dakota, expects to spend as much as $1,500 daily to fuel one combine this season, twice last year’s cost. “You’ve just got to make it work in your budget,” Peterson said.
Farmers can purchase off-road diesel without state and federal fuel taxes, but the discount has not prevented substantial year-on-year increases. Wayne Gularte, who farms about 600 acres near Gonzales, California, said his fuel costs increased about 40%, from roughly $5 to $7 per gallon. He responded by returning some older gasoline-powered tractors to service and parking one diesel pickup.
Higher fuel costs have also increased farm expenses per acre. Michael Langemeier, an economist at Purdue University, estimated that fuel costs have risen by $11 per acre for corn and $7 per acre for soybeans compared with last year. Meanwhile, agricultural economist Nick Paulson of the University of Illinois said farmers could face additional increases in seed and fertilizer costs if elevated fuel prices persist.
The pressure extends beyond farms into freight and food distribution. David Ortega, an economist at Michigan State University, said higher diesel prices increase costs throughout the food supply chain, from farm operations to trucking and retail delivery. “The majority of our food moves on trucks and those trucks use diesel,” Ortega said.
U.S. consumer food prices already increased 2.7% year-on-year in August, according to the latest Consumer Price Index. Ortega said consumers could face further increases as businesses absorb higher transportation costs. However, retailers and existing freight contracts could delay the full impact on consumers.
Produce, dairy and meat face particular exposure because refrigerated trucking requires significant fuel use. Freight rates for apples and pears leaving Washington State’s Yakima Valley reached a four-year high midway through the harvest season. Transportation costs for produce leaving California also increased by 40% to 120% from a year earlier, while diesel prices exceeded $8 per gallon in some California cities.
The higher costs have also raised concerns about the financial position of independent trucking companies. Dean Croke, principal analyst at DAT Freight & Analytics, said independent truckers who pay fuel costs upfront may struggle to absorb additional increases. “We’re about to see diesel price-driven bankruptcies,” Croke said.
Farmers have called for government support as fuel costs rise during the diesel-intensive harvest period. U.S. Senator Roger Marshall asked Agriculture Secretary Brooke Rollins on September 11 to provide temporary relief for farmers facing unexpected fuel expenses. A USDA spokesperson said the department was examining the issue, while Rollins indicated that the agency would announce further action in the coming weeks.