(GasBuddy.com) — Average retail gasoline prices in Illinois have fallen 5.5 cents per gallon in the past week, averaging $2.30/g yesterday, according to GasBuddy’s daily survey of 4,378 gas outlets in Illinois. This compares with the national average that has fallen 0.5 cents per gallon in the last week to $2.33/g, according to gasoline price website GasBuddy.com. 

Including the change in gas prices in Illinois during the past week, prices yesterday were 5.1 cents per gallon lower than the same day one year ago and are 19.5 cents per gallon lower than a month ago. The national average has decreased 8.1 cents per gallon during the last month and stands 10.4 cents per gallon higher than this day one year ago.

According to GasBuddy historical data, gasoline prices on May 15 in Illinois have ranged widely over the last five years:

$2.35/g in 2016, $2.74/g in 2015, $3.78/g in 2014, $3.98/g in 2013 and $3.90/g in 2012.

Areas near Illinois and their current gas price climate:

Peoria- $2.20/g, down 0.5 cents per gallon from last week’s $2.20/g.

St. Louis- $2.25/g, up 7.0 cents per gallon from last week’s $2.18/g.

Champaign- $2.27/g, up 19.3 cents per gallon from last week’s $2.08/g.

“The national average gas price has again declined in the last week, but the road ahead may be a bit bumpier, said Patrick DeHaan, senior petroleum analyst for GasBuddy.com. 

“While the national average fell, several states in the Great Lakes saw average prices rise thanks to a mid-week rally in oil markets that saw oil prices sneak in a net gain for the first week in several, and that may impact prices in the week ahead. Thank Wednesday’s weekly report from the Energy Information Administration for the rally as government data showed a larger than expected decline in oil inventories and gasoline inventories, weighing on markets at the precise time that OPEC chats about extending its crude oil production cuts. Watch both of these factors this week to get a taste for where prices will go to start the summer driving season.”