The national average price of a gallon of gasoline has remained above $4 every day this month, putting August on track to become the most expensive month at the pump in U.S. history. According to AAA, the current national average stands at $4.09, virtually unchanged from a month ago but 88 cents higher than the same time last year. This marks the first time ever that the August national average has exceeded $4 per gallon for the entire month, surpassing the previous August record set in 2022.
Diesel prices are climbing even faster, with the national average now at $5.61 per gallon. That represents a 29-cent increase over the past month and a $1.90 jump over the past year, a 51.2% rise. The spike in diesel costs carries broad economic implications, as diesel-powered trucks and ships move goods across the country and around the world, meaning higher costs are likely to ripple through supply chains and consumer prices.
California continues to bear the heaviest burden, with the highest gas prices in the nation. The statewide average is $5.65 per gallon, while drivers in Mono County are paying $6.81. Diesel in California averages $7.22 per gallon, up from $5.13 a year ago, a steep increase of $2.09, or 40.7%.
The ongoing conflict with Iran is a key factor behind the rising prices, as tankers are trickling through the Strait of Hormuz, a critical chokepoint for global oil shipments. The disruption is putting pressure on both the global economy and American drivers. The situation has been compounded by concerns over the Strategic Petroleum Reserve, which recently dropped below 300 million barrels and is projected to fall to 243 million barrels in the coming months. Experts are watching the reserve levels closely as a potential indicator of future price movements.
While the national average has stabilized over the past month, the year-over-year comparisons remain stark. Regular gasoline is up 27% from 2025, and the sustained high prices are beginning to affect consumer behavior, with reports indicating that Americans are changing their driving habits in response to the costs. The combination of geopolitical tensions, supply constraints, and record-high prices suggests that relief at the pump may not come soon.