WILLMAR -- Gas prices nearly rose to the dreaded $4 mark last week, and were still $3.949 a gallon Sunday at most stations in the Willmar area.
Gail Weinholzer, public affairs director for AAA of Minnesota and Iowa, said gas prices have increased in recent weeks because of Hurricane Isaac, which hit the Gulf Coast before Labor Day and closed the ports, refineries and oil rigs down there for about a week.
Because roughly 25 percent of all fuel consumed in the United States comes from the Gulf Coast, those closures were significant enough to drive up gas prices, Weinholzer said.
"When you keep that statistic in mind, you can imagine how that would constrict supply," she said.
"A restriction to that supply has a negative impact. You typically see gas prices increase."
Even before Hurricane Isaac hit, however, gas prices were on the rise. They have been steadily increasing since the Fourth of July, Weinholzer said.
On Sunday, the average price for a gallon of gas in Minnesota was $3.864, according to the AAA's fuel gauge report website. The last time gas prices were that high was July of 2008.
"Much of the second half of July was above average, and August and now the first half of September are well above average as well," Weinholzer said. "It's a volatile commodity. Fluctuation like this is not all that unusual."
There is some relief in sight, however: Over the weekend, oil refineries began making the switch from summer- to winter-grade fuel, which is pure and costs less to refine, Weinholzer said. The switch should result in lower prices at the pump.
"That will put down the pressure on prices," the AAA spokeswoman said.
Weinholzer predicts that prices will begin dropping by the end of this week, although the decrease will "be gradual," she warned.
"We're not going to see any real significant changes anytime soon," she said. "The caveat being, of course, that it all depends on whether there are hurricanes in the Gulf Coast, or political issues in the Middle East."