How long of notice to give tenants when not renewing lease?

[Kip Thompson]

My wife and I are renting out a townhouse in Vancouver, WA. The lease will be expiring in August 2019 (4 months from now) and we are thinking about not renewing the lease with the current tenants. How long of a notice would you suggest giving them? Just wondering what the pros/cons are of notifying them ASAP vs. waiting as long as possible. These are the first tenants we've ever had (they've been there for 5 years) and so this is uncharted territory.