Refinery issues for western U.S. states and higher crude oil prices pushed the national average price for gas to its highest point since June, retail data show.

Motor club AAA reports a national average retail price for a gallon of regular unleaded gasoline at $2.37, an increase of about 2 cents from last week and 16 cents, or 7 percent, higher than one month ago.

The West Coast continues its streak as the most expensive market in the United States and, according to motor club AAA, a series of refinery issues over the past week have added to the pressure for consumers. Phillips 66 has continued or ongoing issues with its facilities and Chevron's operations are planning maintenance, which may be limiting gasoline supplies for the region.

California has the highest state average price in the nation, after Hawaii, with $2.81 reported for Tuesday. That's a 5 percent increase from the previous month and highlights the state's center as a regional refiner.

The Great Lakes region continues as the most volatile market in the country and 2017 started with new fuel taxes in several states, making the area now one of the more expensive as well. Indiana was among the states in the area that posted the largest weekly decline in gas prices, with the state average price of $2.31 a 3 percent decline from the previous week. Ohio, meanwhile, saw its state average increase nearly 2 percent from last week to $2.36

For the region, federal data show gasoline supplies are abundant and all refineries are running as expected, suggesting the retail market may be behind the curve with its posted prices.

South Carolina has the lowest state average in the country at $2.14 per gallon. The national average on this date last year was $1.97 per gallon.

The price as the pump loosely mirrors movements for crude oil prices, which have been on a steady rise since a November agreement by members of the Organization of Petroleum Exporting Countries to limit production. Retail gasoline prices, according to AAA, have increased 41 of the past 43 days in response to oil markets.

The rise in crude oil prices, however, has brought some operators back to the more expensive shale basins in the United States and markets turned sharply lower Monday following a report from oilfield services company Baker Hughes showing an increase in exploration and production activity in North America.