The average cost for a gallon of gas is trending down across South Dakota according to a new report.

The state's average fell 1.3 cents last week to $3.24 per gallon according to a GasBuddy survey of over 600 stations across the state. That's down 8.2 cents from last month and 43.6 cents from last year.

On a national level, the average cost rose 3.5 cents per gallon over the past week. The national average is nearly 70 cents lower than this time last year.

South Dakota's average price of diesel is $4.12 per gallon, down a nickel from last week and down 20 cents from last month.