For the week ending June 13, the national average price for diesel continued the climb it began in May, according to the U.S. Department of Energy.

The national average rose 4.2 cents for the week, to $2.276 per gallon. Though that is hardly a record high, it is still more than 56 cents higher than prices for the same week in 2004.

California posted the highest prices, coming in at $2.457 per gallon, up 3.6 cents from the previous week. The rest of the West Coast had an average price of $2.364 per gallon, up 2.5 cents.

The East Coast, meanwhile, saw an increase of 4.5 cents to $2.308 per gallon. New England and the Central Atlantic had the highest prices in the area, each coming in at $2.339 per gallon. The Lower Atlantic region posted an average of $2.261 per gallon.

The Rocky Mountain region posted the lowest prices, climbing only 1.9 cents to $2.21 per gallon. The Midwest and the Gulf Coast were not far behind at $2.248 and $2.247 per gallon, respectively.

Meanwhile, prices for light, sweet crude oil stubbornly stayed above $55 per barrel on the New York Stock Exchange on June 14.

Analysts blamed the increase on a general nervousness in the market ahead of the scheduled meeting of the Organization of Petroleum Exporting Countries on June 15. The cartel is expected to raise its daily output to 28 million barrels per day, according to The Associated Press.