SKY · LIGHT POLLUTION
Light Pollution & Dark-Sky Sites
The biggest thing standing between you and a sky full of stars usually isn't cloud or the Moon — it's the glow of artificial light. Here's how dark your sky is on the standard Bortle scale, and the real dark-sky destinations within reach of your city.
The Bortle dark-sky scale
Astronomers rate sky darkness on a 9-point scale, from pristine wilderness (class 1) to a brightly-lit inner city (class 9). It tells you, in plain terms, what you can actually expect to see.
Class 1 · Excellent dark-sky siteThe Milky Way casts shadows; zodiacal light and airglow are obvious. The darkest skies on Earth.
Class 2 · Typical truly dark siteThe Milky Way is highly structured; many Messier objects are naked-eye. Superb stargazing.
Class 3 · Rural skyThe Milky Way shows structure; some light domes on the horizon. Excellent for most purposes.
Class 4 · Rural / suburban transitionThe Milky Way is visible well above the horizon but lacks fine detail. Good dark-sky observing.
Class 5 · Suburban skyThe Milky Way is washed out near the horizon and faint overhead. Brighter deep-sky objects only.
Class 6 · Bright suburban skyThe Milky Way is invisible except near the zenith. Light pollution dominates the lower sky.
Class 7 · Suburban / urban transitionThe whole sky has a greyish glow; the Milky Way is essentially invisible. Only the brightest objects show.
Class 8 · City skyThe sky glows; you can read a newspaper outside. Only the brightest stars, planets and the Moon.
Class 9 · Inner-city skyThe entire sky is brightly lit. Only the Moon, planets and a handful of the brightest stars.
Sky darkness & dark-sky sites by city
132 CITIESEach city page gives an honest Bortle-class estimate for the city centre and lists real, named dark-sky destinations — International Dark-Sky Association places and recognised dark regions — within reach.
USA
USADark-sky sites near New YorkUSADark-sky sites near Los AngelesUSADark-sky sites near ChicagoUSADark-sky sites near HoustonUSADark-sky sites near PhoenixUSADark-sky sites near PhiladelphiaUSADark-sky sites near San AntonioUSADark-sky sites near San DiegoUSADark-sky sites near DallasUSADark-sky sites near DenverUSADark-sky sites near SeattleUSADark-sky sites near MiamiUSADark-sky sites near San FranciscoUSADark-sky sites near BostonUSADark-sky sites near AtlantaUSADark-sky sites near Washington, D.C.USADark-sky sites near MinneapolisUSADark-sky sites near DetroitUSADark-sky sites near Las VegasUSADark-sky sites near PortlandUSADark-sky sites near Salt Lake CityUSADark-sky sites near OrlandoUSADark-sky sites near New OrleansUSADark-sky sites near NashvilleUSADark-sky sites near Kansas CityUSADark-sky sites near St. LouisUSADark-sky sites near PittsburghUSADark-sky sites near ClevelandUSADark-sky sites near CharlotteUSADark-sky sites near IndianapolisUSADark-sky sites near AnchorageUSADark-sky sites near Honolulu
USA · DARK-SKY
USA · Dark-skyDark-sky sites near SedonaUSA · Dark-skyDark-sky sites near MoabUSA · Dark-skyDark-sky sites near Bryce CanyonUSA · Dark-skyDark-sky sites near Death ValleyUSA · Dark-skyDark-sky sites near Big BendUSA · Dark-skyDark-sky sites near Mauna KeaUSA · Dark-skyDark-sky sites near Cherry SpringsUSA · Dark-skyDark-sky sites near Outer Banks
CANADA
MEXICO
PUERTO RICO
BRAZIL
CHILE · DARK-SKY
NETHERLANDS
SWITZERLAND
NORWAY · AURORA
NAMIBIA · DARK-SKY
SAUDI ARABIA
SOUTH KOREA
INDIA
BANGLADESH
INDONESIA
PHILIPPINES
AUSTRALIA
NEW ZEALAND
NEW ZEALAND · DARK-SKY
Make the most of a dark sky
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