If you want to emphasize how cold the weather is, you can say that it is freezing, especially in winter when there is ice or frost.
...a freezing January afternoon.
In summer, if the temperature is below average, you can say that it is cool. In general, cold suggests a lower temperature than cool, and cool things may be pleasant or refreshing.
This is the coldest winter I can remember.
A cool breeze swept off the sea; it was pleasant out there.
If it is very cool or too cool, you can also say that it is chilly.
It was decidedly pleasant out here, even on a chilly winter's day.