Following last week’s brutal cold and severe winter storms, gasoline prices have jumped up to 20-cents a gallon — or more — in some Iowa cities.

Nick Jarmusz, a spokesman for AAA Iowa, says the price you pay at the pump depends on where you live. “For the state we’re seeing an average increase that is about 15 cents,” Jarmusz says, “but in some places, it is more than that.”

He adds, refinery shutdowns in Texas are typically not a major factor in Iowa’s gasoline prices. “Our refining is all done here in the Midwest,” Jarmusz says. “There’s refineries in the Chicago area, there’s refineries up in Superior (Wisconsin) and that’s mostly refining oil that’s coming down from Canada.”

The sizable winter blast that brought Iowa snow and prolonged sub-zero temperatures also dumped flakes on parts of the U-S that rarely see snow, spinning off a deadly tornado in North Carolina and knocking out the power to four-million homes in Texas.

The largest refineries in North America were idled because severe cold cut electricity, water, and fuel supplies across Texas. “There is an indirect effect, because of the commodity nature of gas,” he says. “There’s less of it out in the national market, and that does push prices up, even in places that aren’t directly impacted by that capacity.”

AAA says the average gas price in Iowa is $2.61 a gallon. The state’s most expensive gas is selling in Des Moines at $2.67, while Sioux City has the cheapest gas at $2.49.