Diesel and gasoline prices continued to fall across the U.S. this week, though the economic impact of Winter Storm Jonas may change that, especially in terms of how it affects energy infrastructure.

According to data analyzed by the Energy Information Administration (EIA), average U.S. retail diesel prices declined 4.1 cents this week to $2.071 per gallon, which is 79.5 cents per gallon cheaper compared to the same week in 2015.

Diesel prices dropped in every region of the country this week, the agency noted, with prices the Midwest and Gulf Coast slipping under the $2 per gallon mark: shrinking 3.6 cents to $1.987 per gallon and falling 5.7 cents to $1.957 per gallon, respectively.

The biggest one-week drop in diesel prices occurred in the Rocky Mountain region, EIA said: a 6.3 cent dip to $2.015 per gallon.

California remained home to the highest average diesel price in the U.S. at $2.759 per gallon, though that is down 3 cents per gallon from last week, the agency pointed out.

The average retail U.S. price for gasoline also continued declining this week, falling 5.8 cents to $1.856 per gallon, EIA said, which is 18.8 cents per gallon cheaper when compared to the same week in 2015.

The West Coast is the only region where gasoline prices remain above the $2 per gallon mark: at $2.459 per gallon and $2.141 per gallon when California’s prices are removed from the mix. Both of those price points are higher when compared to the same week in 2015, according to EIA’s numbers: up 13 cents and 4/10ths of a penny per gallon, respectively.

The Midwest recorded the biggest one-week decline in gasoline prices – some 8.2 cents to $1.63 per gallon – while the Gulf Coast just barely retained its grip on the lowest average gasoline price in the country, following a 4.4 cent decline to $1.628 per gallon.