The price of diesel fuel is up this week for the first time in nearly a month, rising 4.5 cents from last week to $3.828. New York crude continued its three-day slide, losing 25 cents a barrel on Monday.

According to the Department of Energy's weekly price survey released on Monday, diesel's seven-week downward trend halted this week. Diesel had dropped nearly 23 cents a gallon over that period. It's still nearly 50 cents a gallon higher than this time last year.

Looking around the country, the lowest average prices for diesel could be found in the Midwest, at $3.717 per gallon, according to the DOE. The highest prices were, as usual in California, at $4.111. Save California, the Central Atlantic region posted the highest prices in the land at $3.996.

Gasoline prices across the country were up 8.3 cents this week, posting a national average of $3.382, 29.3 cents a gallon higher than last year.

Oil prices in New York declined for a third trading day as concerns faded over Iran's ability to restrict world oil supplies. Benchmark crude on Monday fell by 25 cents to end at $101.31 per barrel.

Prices started 2012 on an upswing as Iranian military exercises in the strategic Strait of Hormuz threatened to block shipping channels in response to international sanctions.

The Associated press reports that concerns over a potential confrontation with Iran are easing. Military experts say it's unlikely that Iran would be able to keep tankers from exiting the Gulf, and energy analysts noted that the world remains well supplied with oil, whether or not Iran tries to block the waterway, AP says.