1.
warm (weather, temperature)
Describes pleasantly warm weather or temperature. Written 暖かい for weather/climate.
2.
warm (feeling, personality)
Describes a warm, kind personality or warm feelings. Can also be written 温かい for this meaning.
暖かい (with 暖, meaning 'warmth') is used for weather and climate. 温かい (with 温, meaning 'temperature') is used for warm objects, food, or figuratively for warm personalities. Both are read あたたかい. Also commonly shortened to あったかい in casual speech.