Diesel Prices Today in the U.S.: National Average Hits Record $6.31 a Gallon

Diesel prices in the United States reached another milestone on Wednesday, September 16, 2026, with the national average climbing to $6.3103 per gallon, according to AAA.

That is the highest national diesel average recorded by AAA. A day earlier, drivers were paying an average of $6.2694 per gallon. One week ago, diesel averaged $5.9424, showing how quickly prices have moved.

The increase becomes even more noticeable when compared with longer periods. One month ago, the national average was $5.4460 per gallon. A year ago, diesel cost just $3.7008 nationally.

For truck drivers and trucking companies, the jump means hundreds or even thousands of dollars in additional monthly fuel expenses, depending on mileage and fuel consumption.

California remains one of the toughest states for diesel users. AAA reports an average diesel price of $8.2668 per gallon on September 16, also a record for the state. Washington is averaging $7.3132 per gallon, while Texas, despite traditionally having cheaper fuel, is now averaging $5.9102.

The sharp rise is tied to tight diesel supplies and higher crude oil prices. Reuters reported that U.S. diesel moved above $6 per gallon for the first time this month as global fuel supplies were disrupted and U.S. distillate inventories remained well below their five-year average.

Oil itself remains expensive. On Wednesday, Brent crude was trading around $107 per barrel, while U.S. West Texas Intermediate was near $104, even after prices pulled back from recent highs.

Diesel affects much more than truck stops. Most freight still relies heavily on diesel-powered trucks, meaning higher fuel prices can work their way into transportation rates, groceries, construction materials, agriculture and other everyday products.

For an owner-operator running thousands of miles every week, even a small change at the pump matters. With the national average now above $6.31 per gallon, fuel is once again becoming one of the biggest financial pressures facing the U.S. trucking industry.