South Dakota Gas Prices This Week

In the EIA’s July 2026 (revised August 2026) table of motor fuel taxes, South Dakota’s state taxes and fees on gasoline total 30.0¢ a gallon, tied for the 23rd-lowest of the 50 states and D.C. The 51-jurisdiction average is 33.8¢, and the federal tax adds 18.4¢ everywhere. South Dakota raised its excise tax by 6¢, from 22¢ to 28¢, on April 1, 2015. A 2¢ tank inspection fee makes up the rest of the state figure.

South Dakota has no petroleum refineries, according to the EIA. Its gasoline comes by pipeline and truck from refineries in neighboring states. It has no federal reformulated-gasoline areas.

South Dakota has no weekly EIA series; its seasonal pattern can be read only from the Midwest region’s weekly prices, which over 2004–2025 averaged 9.8% below their annual mean in January and 7.5% above in June.

In the EIA’s annual state series, South Dakota ranked 3rd-cheapest of the 51 in 1972 and 46th in 1979. From 2000 through 2014 its annual average ranged from 3.4¢ below to 10.3¢ above the U.S. average; in 2000 it was 8.8¢ above and ranked 41st. Of those years, it was below the national average only in 2008; the widest gap after that was 7.2¢ above, in 2011, when it ranked 33rd. From 2015 through 2024, beginning with the year of the tax increase, it ranged from 3.1¢ to 8.7¢ below the U.S. average, ranking between 24th and 28th. The highest annual average is $3.86, in 2022. Adjusted for inflation, the highest was 2011 (2012 was within a cent), at $5.04 in 2025 dollars, and the lowest 1998, at $1.07 ($2.11 in 2025 dollars).

South Dakota’s annual average has been below the national figure every year since 2015. That is the longest such run in the state’s EIA series, and it has not moved South Dakota far from the middle of the ranking: it was 28th of 51 in 2014 and 27th in 2024, counting from the cheapest.

The reason is geography. Four of its six neighbors were cheaper still in 2024: Wyoming at $3.12, Iowa at $3.12, Minnesota at $3.15 and Nebraska at $3.21, against South Dakota’s $3.23. Only North Dakota ($3.31) and Montana ($3.33) were higher. Being below the U.S. average in the northern Plains is common, not a distinction.

The largest gap in either direction in the series is still a premium: 10.3¢ above the U.S. in 2001. The deepest discount, in 2020, a year of collapsed demand, was 8.7¢. Over the full decade to 2024 the state’s price went from $3.35 to $3.23, a steeper decline than the U.S. average’s move from $3.31 to $3.29. That is how a state can cross from above the national figure to below it and gain only a place or so in rank: its neighbors fell too.

Counted from the cheapest, South Dakota tied for 41st-cheapest in 1970 at $0.37 and was 44th-cheapest in 1980 at $1.27. The 1990 average of $1.18 tied for 29th-cheapest, and the 2010 average of $2.77 was 31st-cheapest. The 2020 average of $2.08 was 24th-cheapest, and in 2024 the state was 27th-cheapest, which is 25th-most-expensive.

In 2024 South Dakota averaged 11.2¢ above Wyoming, 10.9¢ above Iowa, 8.2¢ above Minnesota and 2.3¢ above Nebraska. It averaged 10.0¢ below Montana and 8.3¢ below North Dakota. Against the U.S. figure of $3.29, its $3.23 was 5.5¢ below.

South Dakota's annual average was above the U.S. figure in 32 of 55 years and below it in 23 of 55, counting 1970 through 2024. The largest one-year fall, 28.2%, came in 2015, and the largest one-year rise, 41.2%, came in 2021. Both years are after 2010, and the EIA estimates each year after 2010 from the change in the state's region, so those moves are the region's moves.

In the EIA table dated July 2026, South Dakota's state taxes and fees on gasoline total 30.0¢ a gallon, which is 3.8¢ below the 33.8¢ average across the 50 states and D.C.