News Photo by Darby Hinkley Alpena gas prices are higher than the state and national averages. Most stations in Alpena, including this Marathon station on U.S.-23 South, sold gas for just under $3.08 per gallon on Friday.

ALPENA — Gas prices are nearing their highest level in four years, with a national average of $2.91 per gallon of regular unleaded gasoline as of Friday, according to AAA.

In Michigan, the cost of a gallon jumped 13 cents over the past month.

Michigan gas prices were higher on Friday than the national average, at $3.03 per gallon, up 58 cents from a year ago, AAA reported. The national average a year ago was $2.52 per gallon.

And Alpena County was on the high end of the state, at $3.08 per gallon. Montmorency County clocked in at $3.01, while Alcona County was at $3.07, and Presque Isle was at $3.09.

“Two gas stations within a couple blocks of each other can have very different prices,” AAA Michigan spokesperson Nancy Cain said on Friday. “We always say, if you see a low price, fill up when you see it.”

She explained that supply and demand, as well as crude oil prices, determine the rates, but that seasonal fluctuations are normal. Prices will continue to climb, she said.

“At least temporarily, it looks like they will,” Cain said.

In the summer, oil companies use what they call a summer blend for the warmer temperatures, and they switch back in the fall.

“The summer blend is better for the environment, but it is more expensive,” Cain explained. “When you end the summer blends, you often see a price increase during the changeover back to the regular blend.”

She added that prices usually decrease in the colder months.

“Typically, you see prices go up a little this time of year, due partly to supply and demand and crude oil prices,” Cain said. “Generally, in the dead of winter, when there are fewer people traveling and less demand, you will see prices go down again.”

While gas prices fluctuate from hour to hour, as of 2:30 p.m. Friday, Alpena gas prices varied slightly from station to station, but not by much, acccording to GasBuddy.com.

The lowest-priced gas in Alpena was $2.99 per gallon, at the Marathon/Admiral at 906 Washington Ave. The next-cheapest gas was 6 cents higher, at $3.05, at three stations: Meijer on M-32, Murphy USA on M-32 in front of Walmart, and Admiral at 2520 U.S.-23 S. All other stations in town were selling regular unleaded for $3.07 per gallon, GasBuddy reported.

According to AAA on Friday, gas cost the most in Hawaii, at $3.83 per gallon, followed by California, at $3.79, and Washington state, at $3.43. It cost the least in South Carolina and Mississippi, at $2.61 per gallon, followed by Alabama, at $2.62.

To view a state-by-state and county-by-county breakdown of gas prices on a color-coded interactive map, visit gasprices.aaa.com.

The highest recorded average price of gas in Michigan was $4.26 per gallon of unleaded, on May 4, 2011, according to AAA.

Consumers can save money at the pump by applying these tips from NerdWallet.com:

∫ Don’t drive aggressively. Rapid acceleration, cruising at high speeds and slamming on the brakes contribute to worse gas mileage.

∫ Keep your tires inflated to the manufacturer’s recommended level.

∫ Don’t use premium gas unless your vehicle requires it.

∫ Use membership cards and rewards club cards to earn discounts at nearby gas stations.

∫ Buy a more fuel-efficient vehicle when it’s time to shop for one.

∫ Drive less — walk or ride a bike instead. It’s better for your body, and the environment, too.

Darby Hinkley can be reached via email at dhinkley@thealpenanews.com, or by phone at 989-354-3111 ext. 324.