The national average price of a gallon of unleaded gasoline fell four cents to $2.53 per gallon for the week ending Feb. 20 and has fallen 3% from its 2018 high of $2.61 that was reached on Feb. 5, according to AAA.

Gasoline remains one cent higher than a month ago and 25 cents higher than a year ago, but motorists in nearly every state are paying less at the pump in recent days. The Midwest and Southern states have seen the most significant declines. This week, only Hawaii and Indiana saw their state average increase.

"The question isn’t how low will they go, but how long will we see prices decline," said Jeanette Casselano, AAA spokeswoman. "A handful of major refineries are undergoing maintenance. If production slows at a high rate and if crude oil prices jump, these events could push pump prices back up in late February or March."

States with the largest monthly decreases include Michigan (19 cents), Illinois (13 cents), Ohio (13 cents), Kentucky (10 cents), Indiana (eight cents), Alaska (five cents), Maryland (five cents), Georgia (five cents), Mississippi (four cents), and North Carolina (four cents).

States with the least expensive gasoline include Texas ($2.27), Mississippi ($2.27), Missouri ($2.27), Alabama ($2.27), South Carolina ($2.28), Ohio ($2.28), Arkansas ($2.32), Oklahoma ($2.33), Tennessee ($3.33), and New Mexico ($2.34).

Meanwhile, the average price of diesel fell 3.6 cents to $3.027, which is 45.5 cents higher than a year ago.