Yes, it is a word. It’s in my Webster’s College Dictionary.
foehn noun \ˈfə(r)n, ˈfœn, ˈfān\
- a warm, dry wind blowing down into the valleys of a mountain esp. in the Alps
I found this word by chance, like I usually find fun words, but reading the dictionary. It was more “I was looking something up and got distracted by a word” kind of thing; a common practice. I want to use it in a poem or in a story. It’s such a fun word to say and spell because it’s not normal. If you click the word above, it will take you to a Wikipedia article about what it really is, since the dictionary is lacking. Here in the north, foehn winds are called a Chinook. My mother, who grew up in eastern Washington always talks about Chinooks. I think foehn is just as fun to say.