Plan your best stargazing nights
Weather forecast, session planning, astronomy calendar, dark sky finder, and community—everything you need to choose the best stargazing night.
Used by over 10,000 stargazers worldwide
4.7
In App Store
"One of the most comprehensive stargazing apps available for stargazers."
"An essential tool for anyone interested in exploring the night sky."
Weather Forecast
Stargazing-optimized weather
Know exactly when to observe with precision forecasts:
Astronomy weather forecast detailsMulti-day Forecast
Cloud cover, seeing, temperature, humidity, wind, dew point—all the data you need.
Expert Mode
Advanced data by altitude and pressure levels for precise atmospheric analysis.
Multiple Models
Choose your preferred weather model (ECMWF, GFS, ICON, and more).
Session Planning
Plan your observation sessions
Organize your stargazing nights with smart session planning:
Astrophotography forecast detailsOptimal Time Windows
Identify the best time slots based on weather, moon phase, and object visibility.
Target Planning
Plan what to observe and when—nebulas, galaxies, planets, and more.
Shared Sessions
Create shared sessions to plan and observe together with friends or fellow stargazers.
Astronomy Calendar
Never miss a celestial event
Stay on top of the best nights for stargazing:
Celestial Events
Moon phases, meteor showers, planetary alignments, and other key events.
Object Visibility
Know when nebulae, galaxies, and planets are at their best visibility.
Dark Sky Finder
Find the darkest skies
Discover the best locations for pristine stargazing:
Dark sky map detailsLight Pollution Map
Find dark sky sites near you or plan trips to the best observing locations.
Global Coverage
Search and forecast for any location in the world.
Community
Connect with other stargazers
Join a vibrant community where you can share your passion for stargazing:
Photo Sharing
Like, comment, and exchange tips with other stargazers.
Equipment Setup
Save and share your telescope, camera, and mount configurations.
What our users say
"A complete application for stargazers, seeing, etc. You can even choose your weather model - a comparison would have been perfect."
Jean G."Very useful for organizing photo shoots."
Tulum Skywatcher"Excellent is the word that describes this application. It surpasses them all."
COSMOS PILOT."Excellent astro app."
Christian S."Everything i need for evaluating the seeing for star gazing. Top"
Edgar pr"I love this app incredible veey easy to see what kind of plaets and moon type is there in sky perfect app"
Isaiah J."For me, it's a really great app and a very good alternative to Clearoutside. The app is regularly updated with new features and, besides a clear overview. I'm completely satisfied with the app"
bmp 80"A complete application for stargazers, seeing, etc. You can even choose your weather model - a comparison would have been perfect."
Jean G."Very useful for organizing photo shoots."
Tulum Skywatcher"Excellent is the word that describes this application. It surpasses them all."
COSMOS PILOT."Excellent astro app."
Christian S."Everything i need for evaluating the seeing for star gazing. Top"
Edgar pr"I love this app incredible veey easy to see what kind of plaets and moon type is there in sky perfect app"
Isaiah J."For me, it's a really great app and a very good alternative to Clearoutside. The app is regularly updated with new features and, besides a clear overview. I'm completely satisfied with the app"
bmp 80"A complete application for stargazers, seeing, etc. You can even choose your weather model - a comparison would have been perfect."
Jean G."Very useful for organizing photo shoots."
Tulum Skywatcher"Excellent is the word that describes this application. It surpasses them all."
COSMOS PILOT."Excellent astro app."
Christian S."Everything i need for evaluating the seeing for star gazing. Top"
Edgar pr"I love this app incredible veey easy to see what kind of plaets and moon type is there in sky perfect app"
Isaiah J."For me, it's a really great app and a very good alternative to Clearoutside. The app is regularly updated with new features and, besides a clear overview. I'm completely satisfied with the app"
bmp 80Are you a museum, planetarium, or science communicator?
Ouranos is open to co-creating custom features tailored to your specific needs. Contact us to imagine innovative tools for your audiences!
Got questions?
Here are some of the most common questions we receive. If you can't find your answer here, feel free to contact us!
The update frequency depends on the weather model you have selected. Click here to learn more about the different models and their update frequencies.
We offer a wide range of weather models from different meteorological services around the world:
Global Models
- ECMWF: IFS (04°, 0.25°), AIFS (0.25°)
- GFS: Seamless, Global, HRRR, GraphCast (0.25°)
- ICON: Global, EU
- GEM: Global, Seamless, Regional, HRDPS Continental
- Météo-France: Seamless, ARPEGE (World, Europe), AROME (France, France HD)
- UK Met Office: Seamless, Global Deterministic (10km), UK Deterministic (2km)
- CMA: GRAPES Global
- BOM: ACCESS Global
Regional Models
- Denmark: DMI Seamless, HARMONIE-AROME Europe
- Japan: JMA Seamless, MSM, GSM
- Netherlands: KNMI Seamless, HARMONIE-AROME (Europe, Netherlands)
- Norway: MET Norway Seamless, Nordic
- United States: NCEP NBM CONUS
We cross-reference these models and apply our proprietary algorithms to provide you with the most reliable astronomical weather forecasts available.
Ouranos evaluates multiple critical factors to determine observation quality:
- Cloud Cover - Clear skies with minimal cloud obstruction
- Seeing - Atmospheric stability for sharp, clear views
- Wind Speed - Calm conditions to avoid telescope vibrations
- Temperature Stability - Stable temperatures to prevent equipment issues
- Moon Phase - New moon periods for darkest skies
- Astronomical Events - Meteor showers, planetary alignments, etc.
Ouranos combines all these factors using advanced algorithms to give you a comprehensive observation quality score, helping you plan the perfect stargazing session.
Our platform offers a free version with essential features. Advanced tools like extended forecasts and detailed sky analysis are available in our pro plans, which include a 7-day free trial.
Yes, you retain all copyrights to your posts and images shared in the community. However, posting grants us a non-exclusive license to share your content on our platform and social channels so we can highlight your work to the broader stargazing community.
Your photos are stored on secure Firebase servers located in Europe West 6 (Zurich). We also leverage the Astrometry API to process images and provide astronomical metadata while ensuring strict data protection.
Yes. We combine multiple global and regional weather models to deliver accurate forecasts anywhere on Earth, and our sky analysis tools work for any location.
For sky analysis we combine several sources: David J. Lorenz's light pollution atlas for artificial sky brightness; SIMBAD for deep-sky objects; Astronomy Engine for planet rise, set and visibility; and the Small-Body Observability API for comets and asteroids.
SIMBAD acknowledgment. This research has made use of the SIMBAD database, CDS, Strasbourg Astronomical Observatory, France. Reference: Wenger et al., “The SIMBAD astronomical database”, 2000, A&AS, 143, 9.
Ouranos is available on iOS and Android.
Yes. Your subscription is linked to your Ouranos account, so it works on both iOS and Android. Just make sure you sign in with the same Ouranos account before using the app on each platform.
Try Ouranos for free
Available on iOS and Android. Start your stargazing journey today!