Translation:It is warm today.
温かい：For objects you can touch or feel, like "warm coffee", "warm shower", and can also used in abstract sense, like "a warm welcome"
暖かい：For surroundings. Like "warm room"
So actually 暖かい is more proper here. But this difference is sometimes ambiguous, and I think even Japanese sometimes mix them together, since I found many websites teaching how to tell these two kanji written in Japanese.