The national average has picked up some downward momentum over the last week, shedding two cents per gallon, and while prices are seemingly relatively stable, upcoming refinery maintenance looms.

Meanwhile, Missouri overtook Oklahoma as the state with the lowest average gasoline prices, falling 3-cents per gallon to $3.015/gal. On the flip side, Hawaii maintained the highest prices in the country, averaging $3.938/gal.

The nation's midsection saw the lowest average prices last week, with a handful of states still holding near $3/gal, mostly due to lower than average gasoline taxes.

Missouri, Oklahoma, Arkansas, and Nebraska were all in the top ten cheapest states, while the Rockies also had Montana, New Mexico, Wyoming, and Utah in the same list. South Carolina and Mississippi also made appearances.

It's likely that during this week, we will see gasoline prices drop below their year ago levels yet again. However, as we're approaching February, the most recent drops will likely reverse as refineries begin their maintenance season, which will see refineries doing critical work preparing for summer at the expense of gasoline output, which will be a contributing factor to an upward rise in gas prices.

Motorists should expect more volatility in late-February through May as the market generally reacts to any unexpected production related issues, and there are generally several issues each year.