Dark Skies

What is a Dark Sky City?

What is a Dark Sky City?

What exactly is a Dark Sky City? It’s a community that commits to preserving dark skies via both policy and practice.

This includes creating a comprehensive lighting policy, generating public awareness, and a demonstration of widespread support by a variety of organizations. 

Flagstaff was named the world’s first International Dark Sky City in 2001. Let’s take a look at how that came about, but first, a little about the importance of limiting light pollution.

Dark skies are important for astronomical research facilities, and instruments such as the Lowell Discovery Telescope and the Navy Precision Optical Interferometer are exquisitely sensitive to even tiny amounts of light pollution. But losing the darkness of night has a host of other impacts. Increasing nighttime sky glow adversely affects ecologically sensitive areas. Disruption of the natural light-dark cycle affects human circadian rhythms and has demonstrable health impacts. The night sky is an important part of many cultural traditions. And many kids grow up in urban centers without ever seeing the Milky Way or a sky dotted with brilliant stars – a source of wonder and inspiration for humankind since ancient times.

Decades ago, Lowell Observatory began working to protect this important natural resource. In 1958, as the observatory partnered with Ohio Wesleyan University to relocate a large research telescope from Ohio to Arizona, scientists became concerned with searchlights that might hinder the dark skies at the proposed new locality. A discussion with city officials led to the creation of an ordinance limiting use of the lights. This was the first such lighting ordinance designed to preserve dark skies. Since then, other organizations such as the US Naval Observatory Flagstaff Station and Flagstaff Dark Skies Coalition, as well as many individuals, have joined the cause for dark skies. Further city and county regulations resulted through the year.

In 2001 the International Dark-Sky Association designated Flagstaff as the world’s first International Dark-Sky City, based on the community’s long lasting efforts at preserving dark skies. 

What Can You Do?

While outdoor lighting is often critical for ensuring safe nighttime activities, common practice often involves using more light than necessary, not strategically positioning lighting and fixtures, and using inferior types of lighting. Such practices often result in glare and excessive brightness that degrades the night sky and wasted energy and resources (looked at in another way, this means overpaying for excessive, unnecessary lighting).  Outdoor lighting codes are designed to minimize these negative practices, requiring smart, safe alternatives that often are cheaper in the long run. Key aspects of these codes are basic and practical to implement.

Minimizing Light Pollution

Put Lights Only Where Necessary

The aim of good dark-sky lighting is to provide light where it is needed – on the ground – while reducing scattered light and glare to the greatest extent possible. One of the simplest ways to do this is to use fully-shielded light fixtures that direct light down.

Use Only as Much Light as Needed

Much light pollution comes from simple over-lighting of areas at night. Depending on the required uses of the land, total lighting levels can be wisely managed to provide enough – but not too much – light. 

Use Light Only When Needed

Many lighting codes include curfews after which signs and business lighting must be extinguished. Simply turning off porch and walkway lights after hours not only saves energy but reduces sky glow.

Dark-sky Resources

The Flagstaff Dark Skies Coalition celebrates and promotes the protection of Flagstaff’s dark skies. This is an excellent place to find a variety of general and technical information about dark skies, as well as Flagstaff’s legacy of preserving them.


Learn More

The International Dark-sky Association (IDA) is the leading international organization for dark-sky protection worldwide. Visit their site to obtain extensive information about dark-sky protection, as well as on how your region or community can join Flagstaff and other communities as a recognized dark-sky place.


Learn More