It's very cold.

Example:

1. It's so cold that the river is frozen.

It's so cold that the stream is frozen.

It's winter and it's very cold, so the man put his hand on his mouth and breathed.

It was cold and cold. The man put his finger on his mouse and blew.

Remember, several months of the year are very cold.

Remember, it is very cold for several months in a year.