Looking at the sky doesn't show anything relevant. It doesn't seem to be affected by binoculars or telescopic eyes, too. Also, when you move the view around, it leaves a trail of "@"s. Unless you move too fast, then it doesn't.
Make a player who can see the sky. Look at the sky. Try moving around.
Feature working as usual.

Seems to be fixed in b10864. Can be closed, I guess?
Please reopen, I see it on later builds and here is a fresh complaint: https://www.reddit.com/r/cataclysmdda/comments/ia06q6/is_the_look_at_the_sky_command_currently_broken/
Although it's not really broken, more like "has glitches" :)
What symbol is used for the blackness? I'm not running the game right now, but I guess that the problem is isolated to one type of weather that uses some symbol or or color that's used for something else on the overmap.
@Ramza13 can you please take a look again? When I set glyph for clear weather all glyphs just become random symbols that change on every load. Is [0] used correctly here https://github.com/CleverRaven/Cataclysm-DDA/blob/2dcc333432989cfcc22e6dd494ac0f7eec9979cc/src/weather_type.cpp#L170 ?
I said it on discord, but I'll say it here too:
That should use the proper unicode character reading function, instead of reading a string and cribbing a character from it, see this for an example.
https://github.com/CleverRaven/Cataclysm-DDA/blob/2dcc333432989cfcc22e6dd494ac0f7eec9979cc/src/move_mode.cpp#L49
Using unicode_codepoint_from_symbol_reader and converting glyph to uint32_t didn't change anything unfortunately. It didn't break more but it still has this glitch.
It works for me after getting rid of char in favor of std::string and unit32_t:
