Cold

Here are some more colorful expressions for "It's cold".

-It's split nippy.
-It's freezing. （凍るほど冷たい・寒い）
-It's frigid.　（非常に冷たい・寒い）
-It's colder than a witch's tit. （とても下品でもよく知られる表現）

You can also use the word "cold" in expressions like this:

-He got cold feet.（彼はおじけづいた）
-He quit smoking cold turkey.　（彼は急にタバコをきっぱりやめた）

There are many ways to use the words "cold", "hot", "warm", and "cool". Try looking them up and finding a few for yourselves!