UNDATED – Average gasoline prices in South Dakota have fallen 1.2 cents per gallon in the last week, averaging $3.62/g today, according to GasBuddy’s survey of 628 stations in South Dakota. Prices in South Dakota are 29.6 cents per gallon higher than a month ago and stand 65.1 cents per gallon higher than a year ago. The national average price of diesel has decreased 11.7 cents compared to a week ago and stands at $5.500 per gallon.

According to GasBuddy price reports, the cheapest station in South Dakota was priced at $3.20/g yesterday while the most expensive was $4.34/g, a difference of $1.14/g. The lowest price in the state yesterday was $3.20/g while the highest was $4.34/g, a difference of $1.14/g.

The national average price of gasoline has fallen 9.4 cents per gallon in the last week, averaging $3.97/g today. The national average is up 3.9 cents per gallon from a month ago and stands 87.4 cents per gallon higher than a year ago, according to GasBuddy data compiled from more than 11 million weekly price reports covering over 150,000 gas stations across the country.

Historical gasoline prices in South Dakota and the national average going back five years:
April 20, 2025: $2.97/g (U.S. Average: $3.10/g)
April 20, 2024: $3.32/g (U.S. Average: $3.67/g)
April 20, 2023: $3.53/g (U.S. Average: $3.68/g)
April 20, 2022: $3.90/g (U.S. Average: $4.10/g)
April 20, 2021: $2.82/g (U.S. Average: $2.87/g)

Neighboring areas and their current gas prices:
Sioux Falls- $3.54/g, down 7.5 cents per gallon from last week’s $3.61/g.
North Dakota- $3.54/g, down 4.7 cents per gallon from last week’s $3.59/g.
Nebraska- $3.55/g, down 4.7 cents per gallon from last week’s $3.59/g.

“Average gasoline prices declined in 48 states over the last week, while diesel prices fell in 46 states, offering a welcome break at pumps, with the national average price of gasoline dipping below the $4 per gallon mark over the weekend,” said Patrick De Haan, head of petroleum analysis at GasBuddy. “However, that relief may prove fleeting. Oil prices surged in Sunday night trading after Iran re-closed the Strait of Hormuz and President Trump signaled further escalation if Tehran does not come to an agreement. With global oil flows remaining at risk, renewed volatility is taking hold, and the continued back-and-forth is making any lasting resolution increasingly fragile. As a result, gasoline prices are likely to rise again in the days ahead, with diesel expected to follow if disruptions persist, and many of the states that exhibit price cycling could see increases in the next 24-48 hours.”