Seattle Trendlines

Monday, September 21, 2026·Charts every weekday

King County’s electric fleet, August 2026

transport
energy
Published

September 21, 2026

Battery-electric against plug-in hybrid registrations in King County, monthly, 2017 to August 2026: the battery line pulls far ahead after 2020, ending at 116,264 against 24,431 plug-in hybrids.

King County had 116,264 battery-electric vehicles and 24,431 plug-in hybrids registered in August 2026 — batteries are 83% of the county’s electric fleet. The battery count is up 9.8% from a year earlier.

The split is the interesting part. Plug-in hybrids were the hedge — battery for the commute, petrol for the mountain pass — and the two lines started the series close together. They are not close now, which is a statement about how far charging infrastructure and range have come rather than about policy.

Registrations are a stock, not sales: this is what was on the road that month.

Source: Washington State Department of Licensing, Electric Vehicle Population, King County, via data.wa.gov (Socrata 3d5d-sdqb). Auto-generated each build.