CHICAGO (CBS) — For the first time in eight months, the average price of a gallon of gas in Chicago has inched above $4.

WBBM Newsradio’s Regine Schlesinger reports gas prices in Chicago on Monday ranged from $3.64 to $4.58.

Patrick DeHaan, senior petroleum analyst for said lingering effects of the harsh winter were to blame for the recent spike in gas prices.

“We’ve been watching the price of ethanol surge in the last two weeks, caused by congestion on rail networks, due to the harsh winter,” he said.

DeHaan said the spike in ethanol prices has added about 12 cents to each gallon of gas you buy, but he expects that to ease soon, though prices should spike again in May when the summer driving season gets underway, and local gas stations have to switch to the more expensive summer blend.

At the same time, DeHaan doesn’t expect this summer’s average gas prices to get anywhere near last summer’s peak of $4.47 per gallon.