It was supposed to warm up today, but I don't think it's very warm at all. In fact, it's quite cold.
この場合、次のような言い方ができますよ。
ーIt was supposed to warm up today, but I don't think it's very warm at all. In fact, it's quite cold.
「今日は暖かくなるって言ってたけど、全然暖かくない。それどころかかなり寒い」
to warm up「暖かくなる」
in fact「それどころか・いやむしろ」
ご参考まで!