Dark Sky Rules: Green Valley vs Tucson
How do dark sky rules rules compare between Green Valley, AZ and Tucson, AZ?
Green Valley and Tucson have similar restriction levels.
Green Valley, AZ
Pima County
Pima County has one of the strictest outdoor lighting codes in the United States, adopted to protect Kitt Peak National Observatory and the surrounding Sonoran Desert night sky. The Pima County Outdoor Lighting Code requires full-cutoff shielding on all outdoor fixtures, limits color temperature to 3000K maximum, and establishes stringent lumen caps by zone.
View full Green Valley rules →Tucson, AZ
Pima County
Tucson's Outdoor Lighting Code requires fully-shielded fixtures, caps color temperature at 3000K, and sets a strict per-acre lumen budget tied to observatory protection zones around Kitt Peak and Mt. Lemmon. Most non-essential lighting must be off by 10:00 PM. Tucson is an IDA-certified Urban Night Sky Place.
View full Tucson rules →Key Facts Comparison
| Fact | Green Valley | Tucson |
|---|---|---|
| Max Color Temp | 3000K (warm white only) | - |
| Shielding | Full-cutoff required all fixtures | - |
| Observatory | Kitt Peak protection zones | - |
| Code Chapter | 18.81 Outdoor Lighting | - |
| First Adopted | 1974 (updated multiple times) | - |
| - | - |
Highlighted rows indicate differences between cities.
Green Valley FAQ
What does the Pima County dark sky lighting code require?
All outdoor lighting fixtures must be fully shielded (full-cutoff) with no light emitted above the horizontal plane. Maximum color temperature is 3000K (warm white). Lumen limits vary by proximity zone to Kitt Peak National Observatory. The code is one of the strictest in the nation.
Can I use bright white LED lights outdoors in Pima County?
No. The Pima County Outdoor Lighting Code limits all outdoor fixtures to 3000K maximum color temperature. Cool-white LEDs (4000K-5000K) and daylight LEDs (5000K+) are prohibited for outdoor use. All fixtures must also be fully shielded.
Why does Pima County have such strict lighting rules?
The code protects Kitt Peak National Observatory, one of the worlds most important astronomical research facilities. The observatory is located within Pima County and requires dark skies for optical and infrared observations. The code has been in place since 1974.
Tucson FAQ
Do I have to replace my existing lights?
Existing fixtures are grandfathered, but any replacement, repair beyond the bulb, or new permit triggers full compliance. Voluntary retrofits are encouraged and qualify for utility rebates.
Are holiday and seasonal lights exempt?
Yes. String lights and seasonal displays are exempt November 15 to January 15. They must point downward and not be aimed at the sky.
What is the maximum color temperature?
New outdoor LEDs are capped at 3000K. Tucson encourages 2200K amber in residential and observatory-proximate zones.
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