Seattle gas prices, September 2026
The Seattle-area average price of regular gasoline was $5.64 a gallon in September 2026, up 20.0% from a year earlier. After inflation the change is up 15.7% — a year-ago gallon cost $4.88 in today’s money.
Two lines, one chart. The orange line is what the pump said at the time. The teal line restates every past price in September 2026 dollars, so the two meet at the right-hand end by construction, and the gap between them further left is inflation. Measured in today’s dollars the record is $6.60 in June 2008; the nominal record is $5.90 in May 2026. Only the real line can answer whether filling the tank costs more than it used to — the nominal one sets a new high every time the dollar shrinks.
Deflated by the national CPI-U, so “today’s dollars” means the latest month the price index covers. State fuel taxes and the clean-fuel standard are inside the number: this is what drivers paid, not what the crude cost. The lines start in January 1998, where BLS resumed collecting a Seattle price after roughly a decade of not publishing one.
Source: U.S. Bureau of Labor Statistics average-price series, regular unleaded gasoline, Seattle CBSA, via FRED APUS49D74714; real series deflated by CPI-U to the latest available month. Auto-generated each build.