Privacy

Hosting

Skywarden and its API are hosted by IONOS SE, Elgendorfer Straße 57, 56410 Montabaur, Germany, on a server in Berlin. Email communications, backups and the self-hosted web analytics also use IONOS infrastructure in Germany.

Using Skywarden involves processing technically necessary connection data, particularly your IP address. This processing provides Skywarden and keeps it operating securely.

The legal basis is Art. 6(1)(f) GDPR. My legitimate interest is the secure and reliable operation of the application.

Your settings and location

You can use Skywarden without an account. Settings such as your observing locations and equipment configuration are initially stored locally in your browser.

For astronomical calculations, the coordinates of your selected observing location are sent to the Skywarden API. This lets the application calculate object visibility, observing times and suitable recommendations, for example.

If you want to use your device’s current location, your browser asks for permission first. Alternatively, you can select a location manually at any time.

Processing provides the features you request on the basis of Art. 6(1)(b) GDPR, insofar as it is necessary for those features.

You can remove locally stored settings through Skywarden or by deleting the website data in your browser.

Your account

If you create an account, I store your email address, the information required for sign-in and the data you sync with your account.

This includes, for example, observing locations, equipment, personal preferences, wishlists and logbook entries.

I need this information to make your data available across devices. The legal basis is Art. 6(1)(b) GDPR.

You sign in using one-time codes sent by email. I use IONOS to send them.

The sign-in cookies required for this are technically necessary and do not require separate consent under § 25(2)(2) TDDDG.

You can delete your account in settings at any time. The associated data is then removed from the active system, unless statutory retention requirements apply.

Clear Sky Alarm

If you enable Clear Sky Alarm, I store your push subscription and alarm settings so I can notify you about suitable observing conditions.

Delivery uses your browser’s push service, for example from Apple, Google or Mozilla. Technical data such as push endpoints and notification information may be transmitted to the respective provider. Depending on the provider, processing may also take place outside the EU or EEA.

You can disable notifications at any time. Processing to provide the alarm you have enabled is based on Art. 6(1)(b) GDPR, insofar as it is necessary for this feature.

Maps and weather data

Skywarden uses external services for maps, location searches and weather forecasts.

OpenStreetMap and Nominatim

When you open a map, map data is loaded from OpenStreetMap. The provider receives technically necessary connection data, particularly your IP address and the requested map area.

Nominatim is used for location searches. Your search queries are transmitted to that service.

You can find more information in the OpenStreetMap Foundation’s privacy policy.

Open-Meteo

For weather forecasts, Skywarden uses the Open-Meteo API, operated by OpenMeteo GmbH in Switzerland.

The Skywarden API sends the coordinates of your selected observing location to Open-Meteo to retrieve the corresponding weather data. Your browser does not connect directly to Open-Meteo for this.

Open-Meteo may store technical access logs, including the requested coordinates. According to the provider, these are deleted after 90 days.

You can find more information at Open-Meteo.

Data is transmitted to provide the features you request on the basis of Art. 6(1)(b) GDPR, insofar as its conditions are met.

Switzerland is covered by an adequacy decision of the European Commission.

External images and links

If you add images to your logbook using external URLs, they are loaded directly from the respective image provider. That provider may receive your IP address and other technical connection data.

If you follow external links, the privacy policies of the respective providers apply.

Usage statistics

To improve Skywarden, I use the open-source software Umami Analytics.

I host Umami myself at analytics.adfr.io on IONOS infrastructure in Germany. No external analytics service provider is used.

Umami collects pageviews, visit times, referrers, browser and device information, and approximate geographical origin.

The software does not use tracking cookies. Pseudonymous identifiers are generated to recognise visits. This involves processing IP addresses and browser information, among other things. The IP address itself is not stored in the analytics data.

Skywarden does not send additional custom tracking events, equipment settings, observing coordinates or account identifiers to Umami.

I use the data exclusively for statistical analysis and to improve Skywarden, not for advertising or cross-site tracking.

Web analytics is enabled only after your explicit consent (Art. 6(1)(a) GDPR). “Necessary only” keeps it disabled; “All” enables it.

Your choice is stored locally in your browser. You can change it at any time through Privacy settings. This does not affect your account or sign-in.

Withdrawal takes effect for the future and does not affect the lawfulness of previous processing.

Analytics data is stored for a maximum of 24 months and then deleted.

Contact enquiries

If you contact me by email, I process your email address and the contents of your message to answer your enquiry.

I use IONOS for email communications.

The legal basis is Art. 6(1)(f) GDPR, my legitimate interest in handling enquiries, or Art. 6(1)(b) GDPR for contractual or pre-contractual enquiries.

The data is deleted once it is no longer needed and no statutory retention requirements apply.

Storage and deletion

Your account data remains stored for as long as your account exists. You can delete individual entries at any time.

When you delete your account, the associated data is removed from the active system, unless statutory retention requirements apply.

Backups are retained for seven days. Deleted data may remain in existing backups until that period expires.

Locally stored settings remain until you remove them yourself.

Analytics data is deleted after 24 months at the latest.

I use IONOS as a technical service provider for processing personal data. Other recipients arise from the features involving external services described above.

Your rights

Under the General Data Protection Regulation, you have the rights of access, rectification, erasure, restriction of processing and data portability, subject to the applicable legal conditions.

You can object to processing based on legitimate interests on grounds relating to your particular situation. You can withdraw consent at any time with effect for the future.

To exercise your rights, you can contact me using the email address below.

You also have the right to lodge a complaint with a competent data protection supervisory authority.

Providing your data is voluntary. An account requires an email address. Location-based calculations require an observing location, which you can also select manually.

Skywarden uses calculations and recommendations for astronomical observations. It does not carry out automated decision-making, including profiling, with legal or similarly significant effects within the meaning of Art. 22 GDPR.

Changes

I update this privacy policy when Skywarden’s technical or legal circumstances change.

Last updated: November 2026

Contact