While Tempest hardware can only be configured to one account at a time, there are simple ways to share your Tempest data with others through the web and mobile app.
Sharing mobile app access:
If you want to share your station data with someone else in the app, have them download the app and sign in to your account. There are no device log in restrictions, so you and multiple family members can all have the app open at the same time on as many devices as you would like.
Sharing web access:
This is the ideal method to share data with others. Every station that reports data publicly has its own web page which can be accessed by guests (users without an account log in). All you need is to share your station's unique URL which includes your station's ID. There is a share button in the mobile app on the device observation screen, at the very bottom.
If someone else cannot see any weather details on your station's web page, make sure your station is enabled to report publicly. You can toggle public data sharing on the website or in the mobile app. Go to Settings > Stations > choose your station > Public Data > Share Publicly (toggle on).
Personal web access: You can access your weather data anytime, anywhere from any browser. Go to https://tempestwx.com/ and login with the same username & password that you created for the mobile app. There is also share button in the bottom left hand corner of the web page, or simply copy the URL from your browser and give it to others.