Statewide average updated daily • Source: AAA
Washington State consistently ranks among the most expensive states for gasoline in the country, typically trailing only California among Western states. The state has the second or third highest gas tax in the nation, a carbon pricing program that adds additional cost to fuel, and significant distance from major refinery infrastructure. The combination makes Washington a reliably expensive fuel market that has grown even more expensive since the state’s cap-and-trade carbon program took effect.
Washington’s state gas tax is around 49 cents per gallon, one of the highest flat-rate fuel taxes in the country. But the larger recent development is Washington’s Climate Commitment Act, which established a cap-and-trade carbon pricing program that took effect in 2023. Fuel suppliers must purchase carbon allowances to cover the emissions from the fuel they sell, and that cost is passed directly to consumers at the pump. Estimates suggest the carbon program adds 25 to 50 cents per gallon to Washington fuel costs on top of the existing tax burden.
Washington has some local refinery capacity in the Puget Sound area, which provides a degree of supply independence, but the state also relies on pipeline imports from Canada and marine shipments. The reformulated fuel requirement in the Puget Sound area adds further production cost.
When Washington’s cap-and-trade program launched in January 2023, gas prices in the state jumped noticeably relative to neighboring Oregon and Idaho, which do not have equivalent programs. Multiple analyses have attributed 25 to 50 cents per gallon of Washington’s price premium to the carbon program, making it one of the most visible and debated policy-driven fuel cost increases in the country.
Did you know? Washington became one of the first states to implement a cap-and-trade carbon pricing program that directly affects gas prices, pushing Washington to near-California price levels almost overnight. Washington has the highest percentage of EV registrations of any state outside California — partly driven by high gas prices making electric vehicles financially attractive. The state’s ferry system, one of the largest in the country, is also among the largest consumers of diesel fuel of any state transportation agency.
Compare today’s average in Washington with nearby states to understand regional price differences.
Learn more about what drives gas prices across the United States.