Where does “火が降る” come from?

火が降る (Japanese) comes from Japanese 火, from Old Japanese 火, from Proto-Japonic poy, from Proto-Japonic po.

Ancestry of “火が降る”, step by step

火が降る traces back through 3 separate lines of ancestry.

via Japanese

StepLanguageWordMeaning
1Japanese"term relating to fire"; a light; a burning...
2Old Japanesea fire; a light
3Proto-Japonicpoyfire
4Proto-Japonicpo

via Japanese

StepLanguageWordMeaning
1JapaneseIndicates the subject of a sentence; conjunction;...
2Finnish-nkaForms nouns, mainly bird names (in dialects) and some toponyms

via Japanese 降る

StepLanguageWordMeaning
1Japanese降るto fall from the sky, to precipitate
Every word from Proto-Japonic poEvery word from Proto-Japonic poyEvery word from Old Japanese