---
title: "iCSC: Clear Sky Chart Viewer - Reviews, Revenue and Downloads in United States | Apple App Store"
description: "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, "
---

# iCSC: Clear Sky Chart Viewer — United States
> Astronomy forecasts for all

![ICSC App Icon](https://is1-ssl.mzstatic.com/image/thumb/Purple62/v4/b9/cf/25/b9cf2599-43e4-4577-0dd0-73f3953542bc/AppIcon-1x_U007emarketing-0-0-GLES2_U002c0-512MB-sRGB-0-0-0-85-220-0-0-0-4.png/434x0w.png)

**Developer:** [Random Widgets](https://apptail.io/developer/random-widgets-vYYb)
**Category:** Weather
**Rating:** 4.9/5 (1,549 ratings)
**Price:** Free
**Bundle ID:** com.randomwidgets.ClearSkyChart
**Store:** Apple App Store
**Country:** United States
**Version:** 1.2.5 (released 2018-02-26)
**Original Release:** 2014-06-22
**Languages:** English

**App Store Link:** [Download on Apple App Store](https://apps.apple.com/us/app/app/id877416121)
**AppTail Page:** [https://apptail.io/app/icsc-clear-sky-chart-viewer-vYe/united-states](https://apptail.io/app/icsc-clear-sky-chart-viewer-vYe/united-states)

## ICSC Description
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.

## ICSC Screenshots
- [Screenshot 1](https://is1-ssl.mzstatic.com/image/thumb/Purple118/v4/4d/83/8b/4d838b9c-6958-a707-07ec-14b533778717/mzl.visxggxo.png/640x960.png)
- [Screenshot 2](https://is1-ssl.mzstatic.com/image/thumb/Purple128/v4/2a/8e/46/2a8e46ac-8d97-9548-e9aa-2ae5dfd3109c/mzl.jkvlkgiq.png/640x960.png)
- [Screenshot 3](https://is1-ssl.mzstatic.com/image/thumb/Purple62/v4/d8/89/03/d889036a-8514-a66b-94f7-f3d7a5fabd56/mzl.phqtrjls.png/640x960.png)
- [Screenshot 4](https://is1-ssl.mzstatic.com/image/thumb/Purple118/v4/a0/21/75/a021754e-560e-7b70-7c3c-324090d21454/mzl.rebtcwdm.png/640x960.png)
- [Screenshot 5](https://is1-ssl.mzstatic.com/image/thumb/Purple128/v4/6a/57/df/6a57df4d-db23-37b4-4b61-04c1af0c0332/mzl.zviqikwk.png/960x640.png)

## ICSC Rating Breakdown in United States
- 5 stars: 1,375 (89%)
- 4 stars: 136 (9%)
- 3 stars: 24 (2%)
- 2 stars: 3 (0%)
- 1 stars: 11 (1%)

## ICSC Reviews in United States

### ***-- "Not supported"
Does kit seem like they support the app anymore.  No updates.  App did not update the weather this week.
-- , 2025-01-03

### ***** "Must have for astronomy!"
We have used CSC for over 20 years, and it has been consistently the most accurate forecast out there!  Updates occur daily, and sometimes, seems to be more frequent than that.  Seldom if ever significantly wrong, and if you want your own map, it is a simple process of uploading your coordinates. My go to whenever considering observing.
-- Zzzmdf, 2024-07-25

### ***** "Great for everyday use"
The only thing that has ever “fooled” this app in my experience is marine layers by the coast (Seattle, Oregon coast, BC). Otherwise, amazing tool, super accurate and easy to use once you get the hang of the charts and legend. Highly recommended
-- Basst82, 2024-04-05

### *---- "Search is useless, missing many locations"
I had a 10 year old clear sky clocks program that no longer worked when I updated to new phone and latest OS. It easily found locations near me

This app only finds a limited number of the Clear Sky Sites available on the website, and you have to know the EXACT naming and wording of the entire clock title.

Clear sky locations I’ve used for decades aren’t in this app’s list.

Useless, wish I could give it Zero stars.
-- macTVman, 2024-04-02

### *---- "no key to charts"
it may be accurate, but with no key to the charts, who knows what color is what. If you're new to Astronomy, it's pretty much useless.
-- Dodeka, 2023-08-18

### *---- "NO TOO IMPRESSED"
This version for my iPhone doesn’t allow me to pick/select favorite locations.  In fairness the version I have on my Mac works fine.
-- Holzydog, 2023-01-31

### ***** "ABSOLUTE NECESSITY FOR ASTRONOMY"
This is my first, and often only, go-to for astronomical seeing details. It’s fundamentally necessary.
-- RN Dave, 2022-11-28

### ***** "Clear Sky Chart"
Simple and useful.
-- USAstronomer, 2022-08-27

### ***** "Awesome"
This is great weather guide fo clear skies. It is my go to app for star gazing. Very accurate. Highly recommended!
-- 3lit31, 2022-08-21

### **--- "Not bad, but horrible viewing on iPad"
The data isn’t bad, but it is all but unusable on my 5th gen iPad Pro 12.9. Tiny text you can’t zoom in on. MyCSC is a much better choice for iPad users.
-- Flea77, 2021-12-02

[View all ICSC reviews and detailed analytics on AppTail](https://app.apptail.io/signup?utm_campaign=ai-crawl&utm_content=reviews)


## ICSC Store Rankings
| Chart | Country | Category | Rank |
|-------|---------|----------|------|
| Top Free | Hong Kong SAR China | Weather | #166 |

## ICSC Discovered Keywords
- astro weather
- clear outside
- astronomy weather
- clear skies
- clear sky
- scope nights
- dark sky finder
- good to stargaze
- astrospheric

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## ICSC Available In
- [United States](https://apptail.io/app/icsc-clear-sky-chart-viewer-vYe/united-states)
- [Canada](https://apptail.io/app/icsc-clear-sky-chart-viewer-vYe/canada)
- [Germany](https://apptail.io/app/icsc-clear-sky-chart-viewer-vYe/germany)
- [China](https://apptail.io/app/icsc-clear-sky-chart-viewer-vYe/china)
- [Australia](https://apptail.io/app/icsc-clear-sky-chart-viewer-vYe/australia)
- [Finland](https://apptail.io/app/icsc-clear-sky-chart-viewer-vYe/finland)
- [Italy](https://apptail.io/app/icsc-clear-sky-chart-viewer-vYe/italy)
- [France](https://apptail.io/app/icsc-clear-sky-chart-viewer-vYe/france)
- [United Kingdom](https://apptail.io/app/icsc-clear-sky-chart-viewer-vYe/united-kingdom)
- [Brazil](https://apptail.io/app/icsc-clear-sky-chart-viewer-vYe/brazil)
- [Hong Kong SAR China](https://apptail.io/app/icsc-clear-sky-chart-viewer-vYe/hong-kong)
- [Switzerland](https://apptail.io/app/icsc-clear-sky-chart-viewer-vYe/switzerland)
- [Colombia](https://apptail.io/app/icsc-clear-sky-chart-viewer-vYe/colombia)
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---

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