As of Monday morning, the state average was $4.01, the auto club group said.
Chicago drivers are paying around $4.75, which is down from the $6-plus motorists were paying in mid-June. Drivers in the metro Chicago area are now paying about $4.30, around .13-cents less than they were one week ago.
The national average gas price was at a high of approximately $5.02 on June 14, according to AAA, and it is currently down to about $3.72 per gallon.
"Less expensive oil usually leads to less expensive gas for drivers," said Molly Hart, spokesperson for AAA -- The Auto Club Group. "This trend has helped pump prices fall steadily for three straight months and, with fall approaching, more markets could soon see prices below $3 per gallon."
U.S. treasury secretary Janet Yellin says gas prices could rise again this winter when the European Union stops buying Russian oil.
"Well, it’s a risk, and it’s a risk that we’re working on the price cap to try to address," Yellen said, referencing an effort by G7 countries to place a price cap on Russian oil.
Yellen explained that this is part of why G7 nations are proposing a pre-cap on Russian oil. Not only is the cap meant to decrease Russian revenue as Vladimir Putin continues his war in Ukraine, Yellen said, it is also aimed at "maintaining Russian oil supplies that will help to hold down global oil prices."
Fox Business contributed to this report.