The price of diesel at the pump rose last week for the first time in eight weeks, to a national average of $2.732 per gallon, according to weekly figures from the U.S. Department of Energy.

Prices had fallen for seven straight weeks for a total of 8.2 cents worth of declines. The DOE's Energy Information Administration reports that the average is 40.5 cents higher per gallon than a year ago.

The highest average prices were reported in the New England region, at $2.862; the lowest in the Gulf Coast region at $2.689.

Oil prices also rose Monday, heading above $79 a barrel for the first time in four weeks in trading on the New York Mercantile Exchange, before ending the day at $78.77.

According to the Associated Press, futures contracts for oil, natural gas and heating oil have all become more expensive this month as snow storms blanketed parts of the country and a sharp drop in supplies of crude and other fuels surprised traders.

However, the cold weather hasn't boosted energy demand above last year's levels. Analysts say U.S. refiners have cut back on oil imports, which has tightened the supply demand of the equation. Also, oil prices are rising as China and India increase the amount of petroleum they're importing.