Light Pollution API
Find the dark skies.
Pxie's light pollution API shows how bright the night sky is at any location, on the familiar 1 to 9 dark-sky scale.
Plan: Free plan.
Coverage: Global land and coastal areas, at about 9 km detail.
What Light Pollution API gives you.
The Bortle scale, for any point
The Bortle class from 1 (pristine dark sky) to 9 (inner city), plus night sky brightness in magnitudes per square arcsecond. Use it to rank viewing sites, label campgrounds or tell users how much of the Milky Way they can expect to see.
Built from satellite night lights
Values come from yearly satellite night-light data at about 9 km detail, so they reflect the latest annual picture rather than tonight. Combine it with the astronomy weather forecast and moon phase to find nights that are clear, moonless and dark.
What the light pollution API tells you.
What comes back
For any coordinates you get the Bortle class and its name, a plain description of what the sky looks like, the sky brightness in magnitudes per square arcsecond, the satellite light level, a ratio showing how much of the glow is artificial, and the year of the data behind it.
Who uses it
Astronomy and star-chart apps rank observing sites with it. Campground and park listings label how dark each spot is. Astro-tourism operators and photographers use it to scout locations before they travel, and planners use it to map outdoor lighting over a region.
Accuracy and limits
Each answer is an estimate for a cell about 9 km across, built from a yearly satellite composite, so it is not a reading at your exact spot. It can miss a single bright streetlight, a hill that hides a town's glow, or a recent new development. Haze and snow can make the real sky brighter. For the most precise figure, use a sky quality meter on site. Open ocean is not covered.
How current is the data
The map is rebuilt once a year from satellite night-light composites, and every response states the data year it used. It shows the typical glow of a place, not tonight's sky, so use it to choose where to go and the forecast to choose when.
Pair it with other Pxie data
Darkness is only part of a good night. Add the astronomy weather forecast for clear and steady skies, the moon phase API for moonless nights, and the sunrise sunset API to know when the sky is truly dark.
Free to start
Light pollution levels are included on the free plan, and each call uses 2 credits.
Related
Bortle 3 · rural sky
Milky Way clearly visible
"How dark is the sky at Lake Louise?"
Pxie answers with the get_light_pollution tool. Environmental data MCP server →
Light Pollution API questions.
Is the light pollution API free?
Yes. Light pollution levels are on the free plan.
What is the Bortle scale?
A 1 to 9 scale of night sky darkness, from pristine to inner city.
How current is the data?
It is built from yearly satellite night-light data.
Help people find truly dark skies.
Start free, or tell us what you are building.
Developers: Light Pollution API docs →