Following record setting cold weather in parts of the U.S. the average cost of diesel has increased for the second straight week and hit its highest price since September, according to the U.S. Energy Department.

It’s up 4.7 cents from a week ago to $3.951 per gallon, but is 7.1 cents lower than the same time a year ago. Over the past two weeks the hike totals 7.8 cents.

These two most recent increases are not unexpected due to shortages in the Northeast of diesel fuel’s sister, home heating oil, with supplies in the region falling to their lowest level since 1990 last week, according to the Energy Department.

Diesel prices increased in all sections of the country, except in the Rocky Mountain region, where it fell 0.3 cent from a week ago to an average of $3.86.

The biggest weekly hikes were seen in the New England and Central Atlantic parts of the East Coast, with both gaining more than 13 cents. This gave New England the highest regional price at $4.305 with the Central Atlantic section having the second highest at $4.281.

The least expensive regional price is the Gulf Coast, where the average increased just 0.3 cent over the last week to $3.775.

In contrast, gasoline has edged down for the second consecutive week, with the national average shedding 0.3 cent from a week ago to $3.292 per gallon.

During this most recent string of declines it’s down less than 0.5 cent but is 24.6 cents lower than the same time a year ago.

Gasoline ranges between a low of $3.083 in the Gulf Coast region to a high of $3.492 in the West Coast region.

Meantime, the cost of oil on Monday fell $1.06 in New York trading, settling at $96.43 per barrel on weaker than expected reports on the economies of the U.S. and China. Compared to a week ago oil is up 77 cents.