暖かい
あたたかい · atatakai · JLPT N5 · i-adj
warm
☀️🧣 暖 = sun 日 + 爰 (sound part); atatakai = warm weather or air
The kanji 暖 carries the sun radical 日, so it is the warm used for weather, rooms and climate. Its twin 温かい (same reading) has the water radical and covers warm food, drinks and hearts. Sun = air warmth, water = touch warmth.
暖 — sun radical 日 + 爰 (yuán, phonetic)
暖 is a semantic-phonetic compound. The 日 'sun' radical carries the meaning of warmth, while 爰 supplies the sound (historically close to 'nuǎn'). It originally described the warmth of sunlight and broadened to mean 'warm' in general — both physical heat and figurative warmth like kindness.