• Gas prices in South Carolina saw a significant increase in late January.
• An expert attributes the rise in diesel prices to cold weather increasing demand for heating oil.
• Seasonal refinery transitions to summer gasoline and geopolitical events are contributing to higher gasoline costs.
• Prices are expected to continue rising as spring and summer approach, a typical annual trend.

South Carolina is seeing a significant increase in gas prices, but one expert explained the price hike is not uncommon for this time of year.

GasBuddy, a North America platform that analyses gas price trends, reported that the average cost of a gallon in South Carolina rose from $2.468 on Jan. 19 to $2.617 on Jan. 26 — a difference of just under 15 cents.

Patrick De Haan, the head of petroleum analysis for GasBuddy, said the cost of diesel gas and gasoline have seen price increases lately. The rise in diesel gas can be explained by a burst of wintery weather facing many U.S. states this week, while the spike in gasoline prices is a little more complex.

According to De Haan, diesel gas prices are on the rise because diesel gas and heating oil are essentially the same product, leading to a spike in diesel demand when temperatures get colder.

“Diesel and heating oil are essentially the same product,” De Haan said. “It’s temperatures that would then cause heating oil demand to go up.”

De Haan went on to say that the rise in gasoline prices may be caused by time of year and recent geopolitical events. According to the analyst, gas prices usually start trending upward later in the winter.

During this time, refineries start to make summer gasoline, which has a lower Reid vapor pressure and is often pricier. It also coincides with spring break vacations, when many people take to the road and drive up demand for gasoline.

“Maybe in a few weeks, we could see prices stabilize or decline slightly,” De Haan said. “But also, beyond that, we’re getting closer to the start of the annual rise in gas prices that happens every spring.

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Another driver for higher gasoline prices is the supply market overseas. The analyst pointed to three situations overseas that could be driving up the cost of a barrel of gasoline, making American consumers feel more of an impact on their wallets at the pump.

He said the ongoing situation in Venezuela, U.S. sanctions on Iran, and an oil field fire in Kazakhstan could all cause the price of gasoline to rise. De Haan said any disruption to global oil supply can be felt by consumers almost immediately.

“Iran is a major oil producer,” De Haan said. “Those sanctions President Trump puts on Iran make it more difficult for them to supply oil to the market, meaning that global oil supply could be negatively impacted by new sanctions.”

De Haan anticipates that the price of diesel will stay higher so long as colder temperatures stick around, but he is hopeful that those prices will start to come down within a few weeks.

As for regular gasoline, those prices could stay high or even rise simply because of the time of year.

“Enjoy these lower prices, because they will start to inch up as we get closer to summer,” De Haan said. “That’s something that happens every year.”

Bella Carpentier covers the South Carolina legislature, state, and Greenville County politics. Contact her at bcarpentier@gannett.com