SIOUX FALLS, S.D. (KSFY) - The national average for a gallon of gas has increased nearly 20-cents since the beginning of the year.
That increase is the largest jump during the months of January and February since 2015.
During the spring months, it's pretty normal to start seeing gas prices increase as we transition into summer and the summer blends.
"Well, there are more additives in the summer-blend gasoline," Marilyn Buskohl, AAA South Dakota public affairs, said. "So, that's why they're more expensive to produce and of course, those costs are carried over to the consumer."
But, there is some good news, prices at the pump are actually 10-cents cheaper a gallon than one year ago.
The reason for the jump is reduced gasoline stock levels and increased demand.
"I think demand is up because people are traveling more," Buskohl said. "You know, going into the summer we always see demand continue to increase because there is a lot more travel in the summer."
South Dakota is in the top ten for largest weekly increases for a gallon of gas, up 6-cents from last week making it $2.33. But, South Dakota is the cheapest across the region. Minnesota is sitting at $2.39 per gallon and Iowa at $2.37.
Some gas stations in Sioux Falls are offering $2.44 per gallon.
Motorists can expect to see gas prices continue to increase as refineries gear up for summer gasoline production.