Gas prices in Washington

Regular gas costs an average of $5.45 a gallon in Washington, and diesel $6.64, based on Washington's figure for the week of September 28, 2026. That's 98 cents above the national average.

Fuel	Washington	U.S. average
Regular	$5.45	$4.47
Diesel	$6.64	$6.38

What gas costs in Washington

Filling a 15-gallon tank with regular costs about $81.75. A 300-mile road trip in a car that gets 25 mpg uses 12 gallons, which comes to about $65.40.

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Frequently asked questions

How much is gas in Washington right now?

Regular gas averages $5.45 a gallon based on Washington's figure for the week of September 28, 2026.

How much is diesel in Washington?

Diesel averages $6.64 a gallon based on the West Coast (excluding California) figure.

How much does it cost to fill up in Washington?

A 15-gallon tank of regular costs about $81.75 at the average price.

Where do these prices come from?

The U.S. Energy Information Administration surveys retail gas stations every week and publishes averages for the nation, regions and nine states every Monday.