AAA Northern California, based in Walnut Creek, reported that California is the country's most expensive gas market at a $4.80 gallon average, followed by Hawaii at $4.51, Washington at $4.28, Oregon at $3.92, and Nevada at $3.87. The top three cheapest gas markets nationally are Kentucky and Kansas at $2.83 and Arkansas at $2.80.

The average gas price in the United States last week was $3.14, making prices in the state about 46.9% higher than the nation's average. The average national gas price is slightly lower than last week's average of $3.17 per gallon.

WALNUT CREEK, Calif. - Gas prices in California have decreased slightly, with the average price now at $4.80 per gallon of regular gasoline.