Last month, diesel prices rose above $3 a gallon for the first time since November 2008. Over the last six weeks, diesel has increased 18.8 cents. This week's average was 91.1 cents higher than the same week last year.
The Central Atlantic and West Coast regions had the highest prices this week, averaging $3.246 and $3.233 a gallon, respectively. The Lower Atlantic and Gulf Coast regions saw the lowest prices, both at $3.087 a gallon.
Meanwhile, the nearly $1 trillion euro-zone rescue package eased investor worries Monday, causing oil to gain 2.3 percent to $76.80 a barrel on the New York Mercantile Exchange, according to reports by Dow Jones. Last week, however, oil plunged almost 13 percent in four days on investor concerns over Europe's debt crisis, increasing petroleum stockpiles and recent reports on the state of the economy, including the rising unemployment rate. Monday's gain was not enough to offset last week's declines, Dow Jones says.