Pima County, AZ Outdoor Lighting: Light Trespass & Shielding (2026)

Pima County Code § 18.79.070(D), part of the zoning code's sign standards, governs light trespass from signs on unincorporated county land, the area outside Tucson, Marana, Oro Valley, Sahuarita and South Tucson, each of which enforces its own sign code. The rule allows illumination but conditions it: D.1 permits signs to be lit 'except where expressly prohibited in this chapter,' D.2 requires every illuminated sign to comply with the county's Outdoor Lighting Code (Chapter 15.12), and D.3 flatly bars a sign's light source from being visible from above (except as the Outdoor Lighting Code allows) or from an adjacent property or street.

A sign permit is required before installing, altering or relocating most signs (§ 18.79.070(E)(2)); the sign-property owner or an authorized representative applies, and the fee follows the schedule the Board of Supervisors adopts. If an applicant misstates or omits a material fact, the zoning inspector can suspend or revoke that permit under § 18.79.070(E)(6). Signs seeking the county's Dark Sky Protection Option at § 18.79.100(A) trade a 25 percent bump in allowed sign area and height for stricter controls: illumination must shut off by 9 p.m., only the sign copy may be lit, the light source is capped at 3000K color temperature and 100 nits, and externally illuminated signs must be fully shielded with top-down light only, with 'light trespass onto any other property prohibited' outright and no exception.