Grey Sky Project is a long-running observation of the Amsterdam sky.

— Daily photographs of the Amsterdam sky 📸
— A timelapse mosaic spanning 4+ years ⏳
— Year-by-year comparisons of the same calendar day 📊

During the pandemic, I bought a Raspberry Pi 3 with a camera module to experiment with. I’m not entirely sure where the idea came from, but it was probably triggered by my wife insisting that the weather in the Netherlands wasn’t as bad as I kept claiming, that there were, in fact, plenty of sunny days.

Four years later, I now have some evidence 🙂

The Raspberry Pi sits on my office window, facing east. Every day at 13:01, it takes a single photograph of the sky. The image is automatically cropped to remove adjacent buildings, leaving only the sky itself.

The daily photo is then synchronized to a GitHub repository. From there, automated workflows update a static website built with Astro, which is deployed to Hostinger. One published image per day.

Over the years, there have been a few technical hiccups: the camera was occasionally moved or even fell out of its "mounting". Still, the system never missed a day.