Gas in Washington averaged $3.21 in 2018 — $4.11 in today’s money
Average, that year
$3.21
In 2025 dollars
$4.11
The average price of a gallon of regular gasoline in Washington across 2018, shown both as it was at the pump and adjusted for inflation to constant 2025 dollars (CPI-U).
Across the year
How Washington prices moved through 2018
Weekly average for regular gasoline. The year’s high was $3.45 the week of October 22, 2018; the low was $2.89 the week of January 8, 2018 — a swing of 19.6%.
View the weekly data (53 weeks)
| Week of | Nominal | 2025 $ |
|---|---|---|
| January 1, 2018 | $2.89 | $3.74 |
| January 8, 2018 | $2.89 | $3.73 |
| January 15, 2018 | $2.89 | $3.74 |
| January 22, 2018 | $2.91 | $3.76 |
| January 29, 2018 | $2.93 | $3.79 |
| February 5, 2018 | $2.96 | $3.82 |
| February 12, 2018 | $2.98 | $3.84 |
| February 19, 2018 | $2.96 | $3.82 |
| February 26, 2018 | $2.95 | $3.81 |
| March 5, 2018 | $2.98 | $3.85 |
| March 12, 2018 | $2.99 | $3.86 |
| March 19, 2018 | $3.06 | $3.95 |
| March 26, 2018 | $3.11 | $4.02 |
| April 2, 2018 | $3.15 | $4.05 |
| April 9, 2018 | $3.17 | $4.08 |
| April 16, 2018 | $3.20 | $4.12 |
| April 23, 2018 | $3.23 | $4.16 |
| April 30, 2018 | $3.25 | $4.18 |
| May 7, 2018 | $3.32 | $4.26 |
| May 14, 2018 | $3.29 | $4.22 |
| May 21, 2018 | $3.34 | $4.28 |
| May 28, 2018 | $3.38 | $4.34 |
| June 4, 2018 | $3.38 | $4.34 |
| June 11, 2018 | $3.36 | $4.31 |
| June 18, 2018 | $3.36 | $4.31 |
| June 25, 2018 | $3.34 | $4.29 |
| July 2, 2018 | $3.33 | $4.27 |
| July 9, 2018 | $3.33 | $4.27 |
| July 16, 2018 | $3.33 | $4.27 |
| July 23, 2018 | $3.31 | $4.24 |
| July 30, 2018 | $3.30 | $4.23 |
| August 6, 2018 | $3.29 | $4.21 |
| August 13, 2018 | $3.28 | $4.20 |
| August 20, 2018 | $3.28 | $4.20 |
| August 27, 2018 | $3.27 | $4.18 |
| September 3, 2018 | $3.29 | $4.20 |
| September 10, 2018 | $3.30 | $4.21 |
| September 17, 2018 | $3.29 | $4.20 |
| September 24, 2018 | $3.29 | $4.20 |
| October 1, 2018 | $3.31 | $4.22 |
| October 8, 2018 | $3.35 | $4.27 |
| October 15, 2018 | $3.41 | $4.34 |
| October 22, 2018 | $3.45 | $4.40 |
| October 29, 2018 | $3.44 | $4.38 |
| November 5, 2018 | $3.43 | $4.37 |
| November 12, 2018 | $3.39 | $4.32 |
| November 19, 2018 | $3.32 | $4.23 |
| November 26, 2018 | $3.28 | $4.18 |
| December 3, 2018 | $3.20 | $4.08 |
| December 10, 2018 | $3.14 | $4.00 |
| December 17, 2018 | $3.06 | $3.89 |
| December 24, 2018 | $3.01 | $3.83 |
| December 31, 2018 | $2.99 | $3.81 |
Year over year
How 2018 compares, adjusted for inflation
2018 was Washington’s 14th-most-expensive year for gas on record, adjusted for inflation — equivalently, the 11th-cheapest of 24 years (2003–2026).
Every grade
Washington fuel prices by grade in 2018
Year-average price per grade. Premium figures are the spread drivers paid for higher-octane fuel that year.
| Grade | Avg / gal | 2025 $ | vs. regular |
|---|---|---|---|
| Regular | $3.21 | $4.11 | — |
| Midgrade | $3.41 | $4.37 | +20.6¢ |
| Premium | $3.54 | $4.54 | +33.1¢ |
Common questions
Washington gas prices in 2018, answered
- What was the average price of gas in Washington in 2018?
- The average price of regular gasoline in Washington in 2018 was $3.21 per gallon — about $4.11 in 2025 dollars after adjusting for inflation, according to U.S. Energy Information Administration weekly data.
- How high did gas prices get in Washington during 2018?
- Washington's weekly average for regular gasoline peaked at $3.45 the week of October 22, 2018 and bottomed out at $2.89 the week of January 8, 2018 — a swing of 19.6% across the year.
- Were gas prices in Washington higher in 2018 than in 2017?
- Adjusted for inflation, regular gasoline in Washington was more expensive in 2018 than in 2017, up 9.9% year over year.
- How does 2018 rank for gas prices in Washington history?
- Adjusted for inflation, 2018 was the 14th-most-expensive year for regular gasoline in Washington out of the 24 years EIA has published weekly prices (2003–2026).