Diesel fuel in Michigan hit an all-time high of $6.54 per gallon, according to AAA Michigan.

The record, reported Thursday, Sept. 17, is $2.83 more per gallon than a year ago. It comes as Iran has largely kept the Strait of Hormuz closed to oil tanker traffic following U.S. and Israeli military strikes in February, WNMU reported.

The price spike lands during harvest season, when Upper Peninsula farms and construction crews burn through diesel at their highest rates of the year. Cristina Benton, director of market and industry analysis at Lansing-based Anderson Economic Group, said the timing compounds the damage.

"The high diesel prices are happening at the peak of the harvesting season, when farmers want to fuel combines and tractors," Benton told WNMU.

Benton said some businesses may try to absorb higher fuel costs to hold market share. But she warned that companies unable to do so will pass those costs to consumers.

The Michigan price exceeds the national average. The U.S. average diesel price first crossed $6 a gallon on Sept. 10, according to GasBuddy data reported by Reuters. Nationally, diesel prices have surged nearly 60% since the February strikes.

The previous all-time record was $5.82 a gallon, set in 2022. Patrick De Haan, GasBuddy's head of petroleum analysis, said diesel broke that mark over Labor Day weekend, WZMQ reported.

Supply remains tight. U.S. diesel inventories stood 13% below their five-year average at 106.3 million barrels as of Sept. 11, according to the Energy Information Administration. Russia's diesel export ban, imposed after Ukrainian drone strikes idled several refineries, has squeezed supply further.

Analysts at Melius Research warned Sept. 14 that the diesel crunch arrives ahead of the U.S. harvesting and heating season, according to Fortune.

Linda Giesecke, director of refined products at Rapidan Energy, said in the Sept. 11 Reuters report that diesel margins are expected to stay "elevated and volatile into early next year."

Regular gasoline prices in the UP have also climbed. AAA data showed Marquette averaging $3.99 per gallon for regular unleaded as of Aug. 31, the lowest average in Michigan. The statewide average on Labor Day 2025 was $3.30, according to WNMU.

President Trump acknowledged Sept. 9 that relief from the oil-price surge may not come until after the November midterm elections, WZMQ reported. No state or federal diesel-price relief program has been announced.