King County’s share of Washington’s EVs, July 2026
48.4% of Washington’s electric vehicles were registered in King County in July 2026 — 138,528 of the state’s 285,934. The share was 57.0% at its height, in February 2017.
A falling share on a rising count is the interesting shape, and it is what this chart shows: King County has more electric cars every month and a smaller slice of the state’s every month. Early adoption was concentrated here — one county held more than half the state’s EVs — and the rest of Washington has been catching up ever since. The story of EV adoption is now happening outside Seattle.
A share of a whole rather than a rate: numerator and denominator are the same Department of Licensing release, so the figure is exact. Note it is not a per-capita measure — King County holds about a third of the state’s people, so a share near half still means EVs are over-represented here.
Source: Washington State Department of Licensing, Electric Vehicle Population, via data.wa.gov (Socrata 3d5d-sdqb). The share is derived at read time from the county and statewide series. Auto-generated each build.