Glenn County, CA Outdoor Lighting: Dark Sky Rules (2026)

Glenn County's Unified Development Code does not adopt a formal International Dark-Sky Association-style lighting ordinance, but it imposes a glare-control performance standard that functions as the county's outdoor-lighting rule. Section 15.560.080 (Glare and Heat), within Chapter 15.560 (Performance Standards), provides: 'All exterior lighting accessory to any use shall be hooded, shielded or opaque. No unobstructed beam of light shall be directed beyond any exterior lot line. Buildings and structures under construction are exempt from this provision.' The same section also limits heat, stating no use shall generate measurable increased ambient or radiant heat at an exterior lot line. These performance standards apply to all uses permitted under Title 15 and are measured at the exterior lot lines (Section 15.560.020(B)). For signs specifically, Chapter 15.620 reinforces glare control: Section 15.620.060(C)(6) requires sign lighting to be arranged so as not to produce glare on other properties and so the light source is not visible from adjacent property or a public street. The county's review authority may, as part of any discretionary approval, require more restrictive standards than the minimum (Section 15.560.030(C)). Because there is no county-specific footcandle or lumen cap or color-temperature standard, the controlling requirement is full shielding and keeping light beams on your own property; questions should be directed to Glenn County Planning & Community Development Services.