WASHINGTON (Reuters) - The average price of U.S. gasoline rose above $3 a gallon over the past week, reaching its highest level since October 2008, the Energy Department said on Monday.

The national price for regular gasoline increased 7 cents from the previous week to an average of $3.05 per gallon, as rising crude oil prices bolstered fuel costs.

Crude oil settled down 51 cents at $91 a barrel on the New York Mercantile Exchange on Monday as a major blizzard in the U.S. Northeast cut down on already thin holiday trading volume.

Diesel fuel prices increased 4.6 cents to $3.29 a gallon, the department said in its weekly survey of service stations.

(Reporting by Ayesha Rascoe; editing by Jim Marshall)