This guide is for general information only and is not legal advice. Laws change — verify current rules with your state DOT or a licensed attorney before relying on this for any legal matter. Read full disclaimer.
The rule
Washington has no statewide bicycle-helmet law that applies to adult riders. No statewide bicycle helmet law. Some municipalities and counties have adopted local helmet ordinances — check local rules before riding.
What this means in practice
Because there's no statewide age mandate, adult riders in Washington aren't legally required to wear a helmet — but cycling-injury research still strongly recommends one. Local cities, school districts, and bike-share programs can impose stricter rules, so check the municipal code wherever you ride.