At least a legend there would be great!
An index/name for the icon by the looks of it.
Not much can be done if you don’t let everyone know what weather integration produces this
Looks like Yr.
It is, as @tom_l suggested, just an index to the icon name.
You can find a full list of icons (and numbers) somewhere on yr.no, but they are restructuring their web site at the moment, so I don’t have a direct link.
Sorry. As Olen correctly guessed, it is the Yr weather integration.
pls check this out: https://github.com/nrkno/yr-weather-symbols
there you have your index.