The national average price of on-highway diesel reached $5.313 a gallon for the week ending July 27, 2026, according to weekly retail price data published by the U.S. Energy Information Administration. That marks the fourth consecutive weekly increase and the highest reading since early May.
The July climb has been steep. Diesel averaged $4.578 a gallon for the week of July 6, then moved to $4.796 on July 13 and $5.134 on July 20 before reaching the current level. The four-week run added roughly 74 cents a gallon to the national average, a swing of about 16%.
The current figure sits below the 2026 high of $5.643 recorded on April 6, but well above where the year opened. Diesel averaged $3.459 a gallon in mid-January, the low point of the year, and held in the $3.40 to $3.90 range through February. Prices jumped sharply in March, moving from $3.897 on March 2 to $4.859 a week later and $5.375 by March 23.
Prices then eased through June, falling from $5.350 on June 1 to $4.668 by June 29, before the current reversal took hold.
Fuel is one of the largest variable costs in over the road trucking, and weekly EIA averages feed directly into fuel surcharge calculations used across contract freight. A 74 cent move over four weeks changes the surcharge math for carriers and shippers alike.
Source: U.S. Energy Information Administration - https://www.eia.gov/dnav/pet/hist/LeafHandler.ashx?n=PET&s=EMD_EPD2D_PTE_NUS_DPG&f=W