Hey Norman @BlackEagle!
Nice to hear that you like my UI.
We are both German speakers, but I think in this forum it helps everyone if we write in English 
The result is then just not always perfect English, but that seems to bother here no one
You can use the data of the Open weather map binding (use the OneCall API). Here you can find a good tutorial how to add it via the UI.
[OH3] Install & Set-up OpenWeatherMap via UI - Tutorials & Examples / Solutions - openHAB Community
Then you can use these items:
Unfortunately, the lightning and lux values are not available. you can simply remove these two f7-chips from the widget code:
- component: f7-chip
config:
iconF7: sun_min
text: =items[props.item_ill].displayState
style:
margin-bottom: 10px
font-size: 16px
--f7-chip-bg-color: rgba(255, 255, 255, 0)
iconColor: "=themeOptions.dark === 'dark' ? 'white' : 'black'"
iconSize: 20
and
- component: f7-chip
config:
iconF7: bolt
text: =items[props.item_strike].state
style:
margin-bottom: 10px
font-size: 16px
--f7-chip-bg-color: rgba(255, 255, 255, 0)
iconColor: "=themeOptions.dark === 'dark' ? 'white' : 'black'"
iconSize: 20