The national average price of a gallon of unleaded climbed 5.9 cents to $2.066 for the week ending March 28, continuing a month-long trend of increasing fuel prices, according to federal data.

Gasoline's national average is now 38.2 cents lower than it was a year ago, as it climbs higher in nine regions tracked by the U.S. Energy Information Administration. For the week, the price climbed highest in the Central Atlantic (9.3 cents to $2.05), on the West Coast (9 cents to $2.57), and on the East Coast (8.2 cents to $2.02).

Among states, California ($2.772) and Hawaii ($2.56) are among the most expensive, while New Jersey ($1.827) now has the cheapest gasoline. There are now 21 states and the District of Columbia with gasoline above $2 per gallon, according to the AAA's Daily Fuel Gauge Report.

Meanwhile, the national average diesel price increased two-tenths of a cent to $2.121 for the week. Diesel is now 70.3 cents lower than a year ago.