Gas prices in Washington

Regular gas in Washington averaged $5.52 a gallon for the week of September 21, 2026. That's +$1.04 against the national average and +1.3¢ from the week before. Over the past year the change is +$1.00. Taxes are a big part of the story: Washington's state gas tax and fees total 60.2¢ per gallon (4th of 51, highest first), and diesel carries 63.2¢. Since January 2015, the gasoline rate has moved +22.6¢.