MOSES LAKE — Gasoline prices continued their upward climb over the past week, with Washington drivers seeing some of the highest prices in the nation as state, local and national averages all increased, according to AAA data. 

The average price for a gallon of regular gasoline in Washington reached $5.51 on Sept. 8, up 19 cents from $5.32 a week earlier. In Grant County, the average rose 14 cents to $5.47 per gallon from $5.33 on Aug. 31, while Adams County increased 21 cents to $5.55 from $5.34. 

Nationally, the average price increased to $4.15 per gallon, up 7 cents from $4.08 one week earlier. 

The latest figures represent a significant jump compared to both a month ago and a year ago. 

On Aug. 10, Washington's average price was $5.14 per gallon, meaning drivers are now paying 37 cents more than they were four weeks ago. Grant County prices climbed 42 cents during that period, increasing from $5.05 to $5.47. Adams County rose even more sharply, jumping 54 cents from $5.01 to $5.55. 

Compared with the same week last year, Washington motorists are paying about $1.05 more per gallon. The statewide average was $4.46 on Sept. 8, 2025. Grant County's average has increased by $1.01 from $4.46 a year ago, while Adams County is up $1.24 from $4.31. 

Washington's average gasoline price started the year at $3.84 per gallon on Jan. 5 and remained below $4 through early February. Prices then began a steady climb throughout the spring and early summer, reaching $5.71 per gallon June 1 before falling through June and much of July. 

The statewide monthly average peaked at $5.74 in May before declining to $5.48 in June and $5.03 in July. August brought another increase, with prices averaging $5.21 statewide before accelerating sharply over the last several weeks. 

Grant County followed a similar pattern. The local average opened the year at $3.79 per gallon, climbed steadily through spring and early summer to a high of $5.60 in mid-May, then retreated below $5 by late July before resuming its upward trend in August. 

The recent increases come as fuel markets across the country experience renewed pressure. 

"Average gasoline prices rose in nearly three out of five states over the last week, while diesel surged in every state," said Patrick De Haan, head of petroleum analysis at GasBuddy. "These are sobering milestones, and until the global refining supply picture meaningfully improves, diesel prices face continued upward pressure while gasoline may seasonally slow in the weeks ahead." 

Washington drivers are also paying higher fuel taxes than they were a year ago. According to the Washington Department of Revenue, the state gasoline tax increased from 49.4 cents per gallon to 55.4 cents on July 1, 2025, and rose again to 56.5 cents per gallon on July 1, 2026. Combined with the federal gasoline tax of 18.4 cents per gallon, motorists now pay 74.9 cents per gallon in state and federal fuel taxes before other costs are added. 

Washington has the second highest gas prices in the nation, only after California at an average of $5.87.  

Despite the recent spike, analysts note gasoline prices traditionally ease after the summer driving season. However, current market conditions and refining concerns have kept prices elevated, particularly in Washington, which continues to post some of the highest average gasoline prices in the United States.