The average price of a gallon of unleaded gasoline rose 8.7 cents to $2.716 for the week ending Aug. 17 following a steady decline since the middle of July when it peaked at $2.83, according to federal data.

Gasoline is now 75.6 cents lower than it was a year ago and declined in five of the nine categories tracked by the U.S. Department of Energy. While the average price fell at least 4 cents in New England and the Central Atlantic, the Midwest saw a 31.6-cent increase. The spike came following the unexpected shutdown of the largest refinery in the region, reports the Daily News Journal.

The most expensive gasoline among states continues to sell in California, where it has reached $3.583 per gallon. Five other states now have $3 gasoline, including Alaska, Nevada, Hawaii and Illinois. At the other end of the spectrum, 13 states have gasoline that's cheaper than $2.50 per gallon. South Carolina's $2.182 gasoline is the nation's lowest, according to AAA's Daily Fuel Gauge Report.

Meanwhile, the average price of diesel fell two-tenths of a cent to $2.615 per gallon. Diesel costs $1.22 less than a year ago.