You can also use the built-in web browser without jailbreaking Kindle: https://github.com/matopeto/kindle-weather-dashboard or my https://github.com/niutech/kindle-dashboard
Check out LILYGO T5 4.7 Inch E-paper based on ESP32 for $33: https://www.aliexpress.com/item/1005002006058892.html
Or you can repurpose an old Kindle: https://github.com/matopeto/kindle-weather-dashboard
I have my old Kindle displaying the weather through the built-in browser, using this code:
https://github.com/matopeto/kindle-weather-dashboard
If you want to display something more, you could just self-host a page.
Just to note... I've been lazy and haven't jailbroken mine yet, and tested out this weather display: https://github.com/matopeto/kindle-weather-dashboard
Now, although the concept of "screensaver" seems silly for a device where the display takes no power to update, I noticed that when I left the web browser up (disabling the screensaver as mentioned in the repo) it chewed through the battery very quickly, in about 24 hours. With the screensaver back on, it's holding a charge much longer. I'm going to have to jailbreak at some point.