Most analysts believe as summer approaches those prices could be headed even higher.
The rising prices could slow our nation's fragile economic recovery and break a lot of household budgets.
A gallon of regular unleaded was going for $3.99 at a Shell on North Avenue Monday.
"Gas is going up, about 20 cents a gallon over the next couple days. It's $3.99 right now, but the cost has gone up dramatically," said Tom Trumbull, Shell manager.
Chicago gas is mostly derived from Canadian crude oil, which has helped to control gas cost locally. But growing unrest about the Iran, the possibility of conflict and restricted oil supply is forcing up prices of other global oil.
"There's a lot of fears that this means that we're going to go to war," said Phil Flynn, energy analyst, PFG Best. "We saw traders, the open interest from traders buying into oil probably at the highest level we've seen probably in six months."
Flynn says despite efforts in Chicago and the rest of country to reduce fuel use, with things like public transportation, the price at the pump for now is out of consumers' control.
"It depends on the Middle East," said Flynn. :If the Middle East situation calms down, you'll see a big drop at the pump, but until then it's going to be a rough go here for the next few weeks."
ABC7 found some savvy motorists navigating the increasing cost of gas.
Calvin Damper fills up in the suburbs where he works before coming home to the city and looks for deals. "A lot of the gas stations, they may knock off 25 cents per gallon if you do their car wash. It's usually automatic. I tend to do that as well especially with the snow," said Damper.
Saleman Cornel Benford uses an app to find the best gas prices and he looks for ways to reduce his overall miles. "When I am out, I take care of all my errands and things while out so that you can save a little bit. You're going to have to spend it regardless," he told ABC7.