Clear Sky Chart
Boring Admin Stuff


Terms of Use

By using pages on this web site you agree to be a fine human being, to respect all sentient life and to not sue me for any reason. So there. I do the best I can for users and sponsors but no contract is formed when you use my website or sponsor.

After all, it's just a weather forecast. In particular I make no statements about the safety of any site for which I provide a weather forecast. (Most of them I've never been to.) Not all clear sky chart locations are public or even physical observings sites. Check with the land owner, local astronomy clubs, or even local law enforcement for physical and safety concerns before attempting to visit sites listed

Clear Sky Charts and all the data on clear dark sky are free to use for everyone through web browsers. But authors of mobile device apps must write me for permission before using my data.

If you miss an observing event, or the 2024 solar eclipse because of an error on in weather forecasting or eclipse times or locations, your redress is limited to my apology. Eclipse watchers should check their eclipse times with the United States Naval Observatory.

Watch the 2024 Solar Eclipse at your own risk. does not provide complete eclipse saftey information. Nasa's eye safety page is a start. No joke. You may suffer partial or complete blindness if you watch the eclipse improperly. Again, by using website, you agree not to sue me.

I get to change the terms of use, or any policy without telling anyone first.

All clear sky charts belong to me, Attilla Danko, even if I use casual phrases like "your chart". They're mine. Mine I say! ...all MINE!..BWAA HA HA HA........

I reserve the right to delete charts that I believe have fallen into disuse. For the moment, that means charts whose legend pages haven't been used in 30 days.

If you sponsor the clear sky charts, I will hold you in highest esteem and thank you by listing you on my webpages for some length of time, but no contract is formed for service.

Linking and Hotlinking

Websites which do not charge admission may link any page at (Websites which do charge admission can do what they like if they first buy me a 100 acre plot under a mag 7.4 sky.)

Websites which don't charge admission, and also don't make revenue from advertising, may display chart images, or preview images, provided each image links my legend page for that chart. Use the sample html that I have provided at the bottom of each chart's legend page. (Again, tedious rules like these may be discarded in exchange for sufficent largesse.)

Do not copy text, source-html or scripts from any page unless you get written permission from me. (Mostly because it just wont work off off my webhost.)


All pages on plus all clear sky chart images and preview images, no matter what website they appear on, are Copyright 2002 - 2022 Attilla Danko.

Any transparency, cloud or seeing forecast map, labeled "CMC" is provided by the Canadian Meteorological Center and is Crown copyright, product of Environment Canada. Seek their permission to display any of their weather maps, even if the maps are sourced from

All light pollution maps are from the Light Pollution Atlas 2020 by David Lorenz. David recalculated the The World Atlas of the Artificial Night Sky Brightness with newer data. Contact David to re-publish his light pollution maps even if you get them from

The ECMWF forecast on clear sky charts is from the Norwegian Meteorological Institute, also known as MET Norway.

Who's Rules?

This website is operated from Ottawa, Ontario, Canada and is governed by the laws of that jurisdiction even for clear sky charts for other locations. I have no idea how to make that sentence funny and clear and the same time.


Email addresses
I save emails from my users and sponsors as long as possible. But does not sell email addresses and does not do mass mailings. (Frankly, even the thought is very offensive.) I never display user's email addresses on my web pages. I never store user's email on any server. So your email is safe even in the unlikely event that servers are hacked.

If you email me, I will only email you with regard to this web site or possibly personal correspondance.

I do not email sponsors to bug them for ever increasing amounts of money (unless they ask me to remind them of expiring sponsorships). I might email sponsors once more about a previous sponsorship.

I may copy you on an email to a third person if that person is asking for changes to a chart that you requested.

Email Safety
I will never send you an email containing unicode characters, 100% html, javascript, active x, java or attachments of type *.scr or *.pif or incredible, urgent or secret offers. If you receive such, it's because someone is spoofing my email address and you should delete the email. If I ever do send someone an attachement, they'll be .txt files or in a zipfile.

I dont use them. No webpage on will set a cookies. That means I don't sell anything. It also means you cannot set any preferences, and there are no cookies that remember which clear sky chart individuals use. (If you want to create a list of individualized clear sky charts, save shortcuts to your desktop.)

But I've asked google to count page usage with Google Analytics which may set their own cookies. I use Google Analytics to figure out when to buy more computers, in what order to update charts (I update the sponsored and most-used ones first) and to identify charts that are no longer used. I also use Google AdSense, which may set their own cookies, to display ads. But I never display ads on sponsored clear sky chart pages.

You can set your browser to reject google's cookies, if you like. I consider your usage of as acceptance of such cookies otherwise.

Chart Site Locations and "Location Privacy"
Links to satellite predictions,the "Sun & Moon Data" page and some other pages may reveal the site's latitude and longitude. Also The road map link on each clear sky chart page shows the chart site's location.

Chart requesters of observatories who do not want their site made quite so public, for security reasons, may ask me for location privacy. I will then do my best to make sure their latitude and longitude does not appear on I also wont show distances to private charts as any less than 24km (15mi). I will turn off the road map, satellite prediction and other nifty, but potentially location-revealing, links on the chart's legend page. I will also turn off the "on click" navigation features of the light pollution and forecast maps linked to the chart's legend page.

Access logs
My webhosters record users' ip addresses and the urls of the web pages they've looked at. They're called "server logs". These logs are usually deleted after a month. They are not made public and are only readable to me and my webhosters. But only I ever look at them; and then only to identify mis-behaving search engines that are loading down my web hosters. Nobody keeps track of who is looking at what.

Confidential Information
There is no confidential information on There are no userids or passwords. Nothing is for sale and there is no shopping cart. If you see anything that looks confidential, for example the latitude and longitude of a clear sky chart site that should not have been shown, email me and I will remove it.

Sponsorships and Taxes

Under Canadian tax rules, I am not a charitable organization and so cannot offer charitable tax receipts.

(begin tax rant) Actually, I pay Canadian income tax on all sponsorships even if sponsors think they are giving me gifts. All payments include HST/GST from sponsorships from Canadians. Sponsorships from people outside of Canada, and are not GST registered, are "zero-rated" for GST. (If you don't know what that means, I envy you.) I consider all sponsorships to be all-taxes included so sponsors need not worry about it. (end tax rant).


I prefer sponsorship. Sponsors are wonderful people. But there aren't enough of them. So I put ads on some pages on I do not place ads on clear sky chart pages that are sponsored.

Ads that are streamed to my pages are from Google Adsense. Info about how Google uses data it collect from displayed ads is here.

To SEOs:

I do not require search engine optimization. Stop emailing me.


"Me" in this page means Attilla Danko. I am sole proprieter of For a full contact list see this.

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