An episode in a series where snow and cold are the order of the day, as opposed to the normal setting.
In many series almost all of the action takes place in mild, clear weather. This allows the cast to dress comfortably, and saves money on weather effects. But some stories need extremely cold weather and/or snow to work. Thus the Cold Snap
This may be an episode that acknowledges that the setting normally has winter, even if all the scenes are shot inside. Or perhaps there's a freak snowstorm in a setting that normally doesn't have cold weather. In some cases, the cast travels to a cold area specifically to enjoy winter activities.
A Christmas Episode
may also be a Cold Snap
episode, but not always.
This is the opposite of Heat Wave
- In the Warrior Cats series, usually 1-2 books in each story arc take place in winter, and oddly enough they seem to have the biggest events happen in them. The fact that it's winter becomes plot-relevant as well, as winter makes it more difficult for the Clans to hunt and usually causes an outbreak of sickness, and the weather occasionally causes events to occur (such as a cat falling through the ice - which leads to a death once and a forbidden romance another time - or the thaw causing floods).
- My Little Pony Friendship Is Magic: The episode "Winter Wrap-Up".
- There was an episode of Rugrats where a snowstorm descended on the town and the babies set off on an expedition to the North Pole.
- The The Ant And The Aardvark cartoon "The Froze Nose Knows" had the Aardvark chasing after the Ant in the winter snow, at the same time dealing with a hibernating bear who trespasses in his home and ends with him falling into a frozen pond. At the end of the cartoon, the Aardvark decides to hitchhike to Palm Springs for the winter.
- The Spongebob Squarepants episodes "Survival of the Idiots" and "Snowball Effect" would be examples.