What does 蒸し暑い mean?
蒸し暑い is a Japanese adjective meaning “humid, sultry” in English. It is written as 蒸し暑い in kanji, むしあつい in hiragana, and mushiatsui in romaji. This word is part of JLPT N3 vocabulary.
Example sentence
明日蒸し暑くなると思う？
Do you think it'll be muggy tomorrow?