The word "freezing" is used as both verb and adjective.
So, the second sentence is grammatically sound, since you are using "freezing" to describe the cold in your hometown.
In your first sentence, Hope you are enjoying the _______________. We would expect a noun in the blank.
For example: Hope you are enjoying the party (noun). When you use a verb or adjective, the sentence structure is not right.
Hope this helps.