[usmannk]

or just option+0, because degree is like a little 0 I guess?

[mattkrause]

Ha! I had been thinking Option-K like Kelvin (also a unit of temperature--but ironically one that isn't properly a "degree". Maybe that should have been a hint!)

Option-zero has a tiny underbar for me, which I think is in Bulgarian(?) abbreviations.

[jwilk]

º U+00BA MASCULINE ORDINAL INDICATOR, I guess?

https://en.wikipedia.org/wiki/Ordinal_indicator