Get told when tonight is clear enough to photograph the stars
Made by rsutcliffe
View profile on GitHub (opens in a new tab)Nightwatch is a free Mac menu-bar app for amateur astrophotographers.
Every 30 minutes it checks the cloud forecast for your site and, an hour before sunset, sends one alert only if there is a long enough clear stretch during full darkness; otherwise it stays quiet. It checks Apple's forecast against a second one (Open-Meteo) and says when they disagree, and it counts thin high cloud as half, since stacked photos can see through it. It also plans which targets are up, accounting for your hills, trees and houses, and suggests exposures for your telescope.
Can I use this?
You'll need A Mac running macOS 14 or later · Free download
Worth knowing Mac only; the creator says a Windows version or phone companion may come later. Forecasts can be wrong, and the go rule (3 clear hours, cloud at 25% or less, by default) is adjustable. Some data it uses, such as 7Timer and the sky-survey images, is under non-commercial terms, which is why the creator keeps it free with no ads. BuildTube has not run or verified this software.
Why it's here
- 82 people have starred it on GitHub.
- Shown on Hacker News (Show HN) on 4 October, with 84 points.
Numbers as of 6 October 2026, from BuildTube’s latest daily refresh.
Behind it
See the code on GitHubBuildTube has not run or verified this project. Everything above is written from what the creator published.
Made this?