Diesel prices across the United States increased for first time in seven weeks in the week ending Jan. 9, rising 4.5 cents as fading concerns over U.S-Iran tensions pushed oil prices down.

The average $3.827 per gallon left the price up 49.5 cents from the same year ago but up 2.7 cents from 12 weeks ago, according to the U.S. Energy Information Administration. The ramp-up in price was the sharpest since the week ending Nov. 21, when prices rose 4.6 cents.

The rise was the steepest in California, where prices rose 6.5 cents to $4.111 a gallon. Despite the uptick in price, the East Coat’s New England region was the only region other than California to see diesel at or above the $4 mark.

Crude oil for February delivery fell 25 cents to $101.31 a barrel on the New York Mercantile Exchange. The decline comes as concerns over Iran’s ability to cut off oil exports recede and the release of a disappointing manufacturing report from Germany.