According to, the average retail cost of a gallon of gas in Colorado dropped two cents in the past week, to an average of $3.21 a gallon.

Nationally, prices dropped by more than a nickel in the past week to an average of $3.34 per gallon.

In Denver, the lowest retail price for unleaded gasoline is $3.07 a gallon, according to

The website says the prices on Sunday were about the same as the same day one year ago, but more than 20 cents a gallon lower than a month ago.