CHICAGO (CBS) — Chicago area gas prices have climbed back to their highest levels in months.

“A lot of stations in the suburbs going up in price anywhere from $2.59 to $2.69 a gallon; that’s the highest price of the year,” said Patrick DeHaan, senior petroleum analyst at

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DeHaan said the increase is due, in part, to refinery maintenance, which will take longer than expected.

“It appears that most maintenance won’t be wrapped up until mid- to late-June, so we’re going to be subject to higher prices than normal, or higher prices than the rest of the country, because of this long extensive refinery maintenance season,” he said.

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Prices on Tuesday were still 50 to 60 cents lower than this time last year.

The average price of a gallon of regular unleaded in the Chicago area was $2.56 on Tuesdayl, but DeHaan said the suburbs could see prices going up 20 to 40 cents per gallon by the end of the day.