Gas prices are averaging $2.66 across the USA, which is 28 cents per gallon higher than a week ago.
But now, he says, things could be further complicated by Hurricane Irma, a Category 4 storm currently forecast to hit Florida.
Diesel prices were not affected almost as much, DeHaan said. "The wholesale price of gas is drifting back down as more refineries get back online".
Regular soared by 34 cents in New Hampshire and 30 cents or more in several other states, including Virginia, Georgia, Massachusetts, Tennessee, and Florida - where residents were bracing for Hurricane Irma.
Looking at gasoline prices in the coming week, the biggest increases to the national average are behind us. "So, when people hear there's a disruption in supply, they run into the station, top off their tanks", he said. Ohio's prices rose 22 cents per gallon in the past week.
Unlike Texas, Florida has no refineries, so Irma will not cause a major spike in prices at the pump, DeHaan said.
Over the past week, gas prices all over the United States have spiked due to a combination of shutdowns of critical oil refineries and pipelines and damages from the storm.
Gas prices spike in Midstate after Harvey, ahead of Irma
With more than 50 inches of rain, Harvey set a record for the greatest amount of single-storm rainfall for the continental U.S. Franklin County and Adams County residents have to pay the highest prices at the pump in the area.
Typically the app is used to search gas prices, but now drivers in the south are reporting outages. This year, he predicts the price at the pump at that time could be right around $2 per gallon.
"We have been working diligently and expeditiously to complete the fix work and restore service following Hurricane Harvey and the unprecedented flooding in the Gulf Coast last week", the press release said. In response, gasoline prices across the USA spiked to their highest level in two years.
"I hadn't really paid attention to the gas prices the last few days, so when I got to the store I thought, 'Gosh, that's outrageous, '" driver Tammy Smith said.
It's not just Harvey driving up gas prices.
Concerns about shortages spread beyond Florida as Caribbean fuel terminals closed and residents began evacuating other coastal US states, including Georgia, South Carolina and North Carolina. Motorists in some areas may start to see relief as refineries get back online and gasoline begins to flow again.
"RaceTrac is proactively working to mitigate supply issues caused by the effects of Hurricane Irma", said a statement from RaceTrac spokeswoman Liz McIntyre.