Gas prices continue to decrease slightly as it gets closer to the Memorial Day holiday weekend. The average price for a gallon of regular unleaded gasoline fell 1.9 cents last week. Data that was revealed by Gas Buddy experts, this falling trend will still be relevant even during the holiday weekend. As of Monday morning, May 24, the national average for a gallon of gas was $3.02 gallon. Gas prices increased by 4.8 percent in comparison to last month and were up 107 cents from last year. Currently the average price of gas in Illinois is $3.231/gallon. Currently, in Missouri the average price of gas is $2.756/gallon and in Kentucky the average price for a gallon of gas is $2.876/gallon.