Plymouth, MN Outdoor Lighting: Dark Sky Rules (2026)

06, Subd. 1 states the exterior lighting rules exist to permit reasonable night lighting for safety and commerce while minimizing glare, obtrusive light and artificial sky glow, conserving energy, and protecting the environment from man-made night lighting. The City Council assigns every parcel to one of four Lighting Zones (LZ0 natural areas, LZ1 low-density residential, LZ2 higher-density and commercial areas, LZ3 by conditional use permit only) shown on the official Plymouth Lighting Zone Map kept at City Hall. Non-residential lighting systems must be extinguished or dimmed at least 50 percent at curfew under Subd.

in LZ2, and midnight in LZ3 (conditional use permit only), or close of business if later. Low-voltage landscape lighting must go dark at curfew or one hour after closing, whichever comes first. Subd. 4(f) flatly bans mercury vapor lamps, luminaires aimed only toward a property line, and fixtures that confuse or hazard traffic. Aerial lasers and skytrackers are prohibited outright except by administrative permit under Subd. 7(a). Lighting installed before the ordinance's effective date is legally non-conforming, but replacing 50 percent or more of a site's fixtures in one year triggers full compliance under Subd. 4(h).