About Night Sky Index

Night Sky Index is an independent guide to the night sky. We rate the darkness of hundreds of stargazing spots across the American Southwest, Spain and Portugal with a Sky Score out of 100, computed from public scientific data: NASA Black Marble satellite radiance, ERA5 cloud climatology from Copernicus, and local moon computation. Nothing is guessed and nothing is crowd-sourced — every score comes from the same documented model, calibrated on reference dark-sky sites. The full method, including its limits, is on the methodology page.

Around each spot we list places to stay, rated for the darkness measured at their own location, and we cover the sky events worth planning a trip for — starting with the total solar eclipse of August 2, 2027.

The site is free and reader-supported: booking links are affiliate links, and we may earn a commission when you book through them, at no extra cost to you. Affiliate relationships never influence the data — details in the affiliate disclosure.

Who makes it

Night Sky Index is built and maintained by Emilien, an independent developer based in France, who writes the model, runs the pipeline and answers the mail. There is no editorial team and no sponsored placement: what changes a score is a better dataset or a reported error, nothing else.

What we publish, and what we hold back

We computed a score for every spot in our database, but we only publish the pages that have earned a reader's attention or carry a name people look for: 57 spot pages, alongside the eclipse guides. A directory that wants to be found for every pull-out in the desert is not a guide, it is noise, and we would rather be small and right.

Since November 2026 the index is no longer updated: scores and the stays around each spot are as measured in August and September 2026.

Spotted an error, or taken an SQM reading at one of our spots? We genuinely want to know: hello@nightskyindex.com.