The national average for a gallon of diesel dropped 1.1 cents to $1.70 according to the U.S. Energy Information Administration (EIA). The decline marks the fifth straight week in a row of price relief and further reinforces EIA’s summer outlook of easing fuel costs. (See “Diesel Prices Set to Cool Over Summer”)

All regions posted a decline, except for the Lower Atlantic, which held at $1.636 per gallon. The Rocky Mountain region recorded the largest drop, down 4.4 cents to $1.835. California remains the most expensive region to fill up— and the only region breaking the $2 mark, down 3.2 cents to $2.019. The cheapest region to fill up is the Gulf Coast, down 1.2 cents to $1.623.