CHICAGO (CBS) — Average gasoline prices in Chicago increased about a nickel per gallon in the past week and is $1.17 a gallon more expensive than a year ago.

The average cost for a gallon of regular is now $4.08, well above the national average of $3.67, according to

Prices are on the rise after a month-long dip. In late May, the average cost of a gallon of gasoline stood at $4.27, before falling to below $4.

However, a year ago this month, drivers were paying less than $3 a gallon.

The most expensive fill-up, according to ChicagoGasPrices? The Mobil at 1106 W Fullerton Ave. and Seminary Ave., where a gallon is selling for $4.51.

Across the border in Northwest Indiana, gasoline is selling for around $3.80 a gallon on average.

Wildly fluctuating prices are obviously nothing new. The United Press International reported in January of 1974, wholesale gasoline prices spiked 10 percent to over 50 cents a gallon as experts warned of price gouging at the pump.

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