Gasoline prices in Butler County have soared by nearly 40 cents a gallon from a month ago.

They're up a nickel in the past week.

Can't get much higher, right? Wrong.

“It's not over yet,” Bevi Powell, vice president of community relations at AAA East Central in Pittsburgh, said. “The price is trending upward heading into the spring,”

She's not the only gas tracking expert who predicts motorists in the weeks ahead will be paying more — and fuming more — to fill 'er up.

“We're getting a bit of a pause in the price now,” Gregg Laskoski, a senior petroleum analyst with GasBuddy.com, a website that gauges prices at the pump, said, “but they're going to go higher.”

In the last month alone, the average price per gallon in the county has risen from $3.48 to $3.85, according to AAA. The national average is $3.72.

What's fueling the price surge are the usual suspects — higher international crude oil prices, greater global demand and worry over refinery capacity.

Commodity traders are also to blame, said Laskoski.

“There's a great deal of speculation,” he said. “And speculation is usually driven by investors hedging against the weak (U.S.) dollar.”

Investors, he said, have poured billions of dollars into energy commodities, primarily oil, since oil is often used as a hedge against inflation by investors.

And because oil is bought and sold in dollars, it essentially becomes cheaper on the foreign markets when the dollar falls.

Commodity buyers are trading up oil futures, too, as they've seen the stock market rise. Traders aren't dummies, Laskoski is quick to remind.

“They know that a higher stock market means a stronger economy,” he said. “And that means more energy consumption.”

He sees global demand picking up, especially in China.

There's another seasonal factor that will drive the price up at the pump soon, Powell said.

“Gasoline prices tend to increase at this time of year because refineries are shifting production from winter blends to the summer blends,” she said. “It's more expensive to manufacture the summer blends.”

During the switch over from winter to summer formula fuel, refineries go offline and perform maintenance, which further reduces capacities.

East Coast refineries as of Thursday were running at 81 percent capacity, Laskoski said. That compares to December, when those same refineries were at 91 percent.

But despite all the pain at the pump, there's reason to take heart, say the analysts.

“There's going to be some incremental decline once the prices peak in April,” Laskoski said.

Powell predicts lower gas costs for motorists this summer than in 2012.

“And a lot lower than the (region's) all-time high of $4.05 in June 2008,” she said.”