Napa County, CA Short-Term Rentals: Noise Rules (2026)

Napa County does not maintain a separate STR noise ordinance with quiet hours, amplified-sound rules, or party-house penalties because short-term rentals of dwelling units are not a legal use in the unincorporated county under Section 18.104.410. Where neighbors report loud guests or party noise at a property believed to be operating as an unpermitted STR, two enforcement tracks run in parallel. First, Code Compliance (Napa County Planning, Building and Environmental Services, 707-253-4417) investigates the underlying transient-occupancy violation under Section 18.104.410 and the back-tax liability under Code Chapter 3.32. Second, the Napa County Sheriff's Office responds to active disturbances under conventional California disturbing-the-peace and nuisance authorities (Penal Code Section 415; Civil Code nuisance provisions) and under the county nuisance code. Because the STR itself is prohibited, there is no compliance defense available to the operator: 'We were quiet by 10 p.m.' does not legalize a transient commercial occupancy that the zoning code does not allow. Cities within the county have their own STR programs with quiet hours (the City of Napa's hosted STR program, for example, imposes a 10 p.m. to 7 a.m. quiet-hour window under its municipal code); those city rules do not apply to addresses outside city limits.