Photo via Wikipedia.

Photo via Wikipedia.

The national average price for a gallon of unleaded gasoline increased 3.9 cents to $2.339 for the week ending May 30, according to federal data.

Gasoline remains 44.1 cents lower than a year ago, as it increased in nine regions tracked by the U.S. Environmental Information Agency. The regions saw increases of between 1.5 and 6 cents with the sharpest price hike coming in the Midwest, which increased 6 cents to $2.34 per gallon.

Five states and the District of Columbia ($2.508) now have gasoline above $2.50 per gallon, including California ($2.814), Hawaii ($2.696), Alaska ($2.611), Washington ($2.603), and Nevada ($2.501). Mississippi now has the lowest average price at $2.087, according to the AAA's Daily Fuel Gauge Report.

Meanwhile, the average price of diesel increased 2.5 cents to $2.382. Diesel is now 52.7 cents lower than it was a year ago.