The average price for a gallon of regular unleaded gas in Iowa is just below three bucks. Data from the Iowa Office of Energy Independence indicates that on December 15th, the average price of gas with a 10% ethanol blend was $2.84 a gallon in Iowa.

That’s almost 11.5% higher than the same grade of gasoline was selling for in the middle of last December. Diesel prices have risen even higher — 18% above last December’s level. On Tuesday, the national average price for a gallon of regular unleaded was $3.05.

Pump prices have spiked up in Iowa in the past week, climbing to an average price of $2.99.9 a gallon. A retired oil company executive recently predicted gasoline prices would rise to five dollars a gallon within the next few years.

An energy data analyst with the Iowa Office of Energy Independence, Katherine Fought, blames the cost of crude oil, which has topped 91-dollars a barrel. She says the gas prices following the price of crude oil at this point, which has increased dramatically since September and it does continue to go up. Fought says there are some other factors influencing the gas prices.

“Increased demand from developing countries, the weakening U.S. dollar is another reason, and increased strength in the equities market,” Fought says. Heating oil costs are also on the rise, climbing 16-cents in the last month.