iPhone Screenshots


Choosing when and where to observe is hard. It's a pain to take out your telescope and then having to put it away when clouds quickly roll in.

Well, now you don't have to. With iCSC on your iPhone, you can easily search around for the best location, using Clear Sky Charts published by Attilla Danko.

The Clear Sky Chart, invented and maintained by Attilla Danko, shows at a glance when, in the next 48 hours, one might expect clear and dark skies for a specific observing site.

There are over 4600 charts available for North America, with data provided by Allan Rahill of the Canadian Meteorological Center. These charts provide Cloud Cover, Transparency, Seeing, Darkness, Wind, Humidity, and Temperature. Users can also enable a legend to help read the charts.

iCSC allows users to find charts by title, location, or with a map. Users can then save the charts that they use often.

While Clear Sky Charts are targeted at astronomers, anyone who wishes to look into the heavens, or needs a highly accurate sky forecast can benefit from iCSC: Clear Sky Chart Viewer.

What’s New

Version 1.2.5

Sorry - we let a bug slip through! The issue with favorites has been fixed.

Ratings and Reviews

4.9 out of 5
118 Ratings

118 Ratings

Quiescent ,

Basic but Useful

I’ve experienced several odd crashes and strange bugs but for what I need it for, it works well enough and always has reliable information. I use this app to check night sky conditions for stargazing, meteor shower conditions and chasing the aurora borealis. It has saved me from driving an hour out of town for the lights, based on knowing the humidity and darkness (moonlight and such) aren’t ideal, or if / when a weather system is blowing in. I’ve been using this app very frequently (several times a week) for a few years, now. I’d hate to be without it!

Tdes64 ,

Great little app

I use it all the time. Could use some improvement on the scaling side

Remi ,

Good app, would love widget

I would really really like a widget for a quick view of a favorite chart.


Random Widgets Inc.
18.7 MB

Requires iOS 11.0 or later. Compatible with iPhone, iPad and iPod touch.



Age Rating
Rated 4+
© 2018 Random Widgets Inc.


  • Family Sharing

    Up to six family members will be able to use this app with Family Sharing enabled.

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