FineStella
Overview
Section titled “Overview”FineStella is a web app for stargazing. Pick a destination and a time, and it shows how cloudy the sky will be there and how the clouds are moving. It runs in the browser, with no sign-up or installation.
Web app: https://finestella.com/
Repository: kazweda/finestella
FineStella was first released as “Sky Window” and renamed in November 2026 because other apps and services already used that name. The old URL redirects to the new web app.
Features
Section titled “Features”- Choose a destination by tapping the map or searching for a place name
- See total cloud cover and low, mid, and high cloud cover for any hour over three days, starting today
- Overlay cloud cover within about ±130 km on the map and play it forward to see how the clouds move
- Show the direction and speed of cloud movement, based on winds near cloud level
- Highlight the best time to observe each night: dark hours when total cloud cover stays at 30% or below
The app shows forecasts only, not live satellite images. Forecast data comes from Open-Meteo, and the base map from the Geospatial Information Authority of Japan.