Isleton, CA Outdoor Lighting: Dark Sky Rules (2026)

Sacramento County does not impose a standalone, county-wide 'dark sky' lighting ordinance on detached single-family homes in unincorporated areas. Instead, light-pollution controls are embedded in the Zoning Code's development standards for specific uses. For multifamily housing, the lighting standards (in the Section 5.4.3 development standards) require fixtures to be 'constructed with full shielding and/or recessed to reduce light trespass to adjoining properties,' directed downward and away from adjoining properties and the public right-of-way 'so that no light fixture directly illuminates an area outside of the site,' and require new fixtures to be 'full cut-off fixtures as defined by the Illuminating Engineering Society of North America' (IESNA). Lights must also be placed on a timer or photoelectric cell to operate from one-half hour before dusk to one-half hour past dawn. The parking-area lighting standard, Section 5.9.4.G, applies the same full-shielding, full-cut-off, downward-direction requirements and applies them to existing businesses. County subdivision-level lighting standards discourage nighttime sky pollution and call for compliance with IESNA illumination levels, directing lighting away from adjacent areas to minimize spillage. These provisions function as dark-sky-style protections for the regulated uses, but a homeowner installing residential exterior lighting is governed mainly by nuisance and light-trespass principles rather than a dedicated fixture mandate.