- French narrator
- Realistic Fish Head
- Old Man Winter (mentioned)
- Gary the Snail
- SpongeBob SquarePants
- Incidental 27
- Snow fish
- Snow whale
- Kid fish
- Incidental 158
- Snow mermaid
- Eugene H. Krabs
- Mrs. Puff
- Sheldon J. Plankton
- Patrick Star
- Squidward Tentacles
- Meteorologist (heard only)
An iceberg travels across the surface of the ocean and stops over Bikini Atoll, causing it to snow underwater in Bikini Bottom. Johnny Elaine comes in and tells the audience that it is now snowing in Bikini Bottom. Everyone notices and starts to have fun in the snow, while SpongeBob and Patrick decide to have a snowball fight. Meanwhile, Squidward is relaxing at his house, sitting near a fire and drinking a hot cup of tea. He hears the sounds of SpongeBob and Patrick's snow fort building and tells them to quiet down. The duo try to convince him to come out and play with them, both trying to get him on their own side, but Squidward shoots both of them down, dismissing snowball fighting as childish.
Squidward decides that, as entertainment, he will watch them fight, hoping they will get hurt. However, SpongeBob and Patrick took Squidward's words to heart and signed a peace treaty. Squidward tries to convince them to continue for his entertainment, but repeatedly gets hit with a snowball by Patrick as a result. He then decides to throw a snowball at SpongeBob and Patrick, but misses both of them. SpongeBob and Patrick then proceed to duck behind their fort and mercilessly begin to pelt Squidward with snowballs. Afterwards, a frustrated Squidward proceeds to throw a snowball and hits SpongeBob right in the face. He quickly begins to enjoy himself but soon becomes exhilarated and starts to relentlessly pelt SpongeBob and Patrick with more snowballs. After Patrick is hit by a snowball containing Squidwards's clarinet, he and SpongeBob decide that Squidward is taking the snowball fight far too seriously and sneak off.
When Squidward notices that the snowballs have "stopped falling," he becomes paranoid and riled-up. Realizing his fort is too small, Squidward decides to make it bigger and eventually builds it to the size of a tower, later to be known as Fort Squidward. When an overhead tree branch begins to keep dropping snow on his head, Squidward believes snowballs are being thrown at him by SpongeBob and Patrick and repeatedly hurls out snowballs in random directions.
Meanwhile, SpongeBob and Patrick relax in the pineapple, watching TV while drinking hot chocolate and eating popcorn. SpongeBob faintly hears Squidward's yelling for a moment and asks Patrick if he heard something. Patrick replies "no."
There is a scene which shows Squidward inside a snowman dungeon which he made and yelling "I'll bring them to my snow dungeon and extract their valuable secrets." This scene never made it past the storyboard.
|( ‣ ) Associated production music|
|( • ) Original music|
|( ◦ ) SpongeBob music|
‣ America, A Dream Comes True - Gregor F. Narholz [opening]
‣ Jolly Sleighride - Ib Glindemann [Bikini Bottom covered in snow]
‣ Danger Zone - Mike Sunderland ["This is serious, SpongeBob."]
• Idea Sting - Nicolas Carr ["Snowball fight?"]
• Vibe Q Sting - Nicolas Carr [Patrick makes a cube/Patrick makes a rectangular pyramid]
• Unknown Vibe Links - Nicolas Carr [Patrick makes DNA]
• Battle Begins - Nicolas Carr [SpongeBob and Patrick glare at each other]
‣ Romantic Waltz - Geoffrey Herman [Squidward relaxing]
‣ The Merry March (a) - Paddy Kingsland [SpongeBob and Patrick building forts]
‣ Tomfoolery - David Snell [Patrick choking on snow]
‣ Comic Walk - Sidney Torch ["Snowball fights are for immature children."]
• Vibe Q Sting - Nicolas Carr ["Hmm..."]
‣ Comic Walk - Sidney Torch ["Now there's something I'd actually like to see!"]
‣ Tympup A - Sammy Burdson, John Charles Fiddy [SpongeBob and Patrick shake hands]
‣ Comic Walk - Sidney Torch [peace treaty]
• 12th Street Rag 3 - Nicolas Carr, Sage Guyton, Jeremy Wakefield [Squidward trying to start another snowball fight]
‣ Marshall Strength Link - David Snell [SpongeBob and Patrick throw snowballs at Squidward]
• Idea Sting - Nicolas Carr ["That was actually kind of exciting."]
‣ I Saw Three Ships 29 (c) - Richard A. Harvey ["I have never felt so live."]
• Earl's Revenge - Sage Guyton, Jeremy Wakefield [Squidward throwing snowballs]
• Vibe Sting - Nicolas Carr ["What's going on?"]
• Sponge Monger - Sage Guyton, Jeremy Wakefield [ending]
- This episode is available on the Christmas, Complete 3rd Season, The Best 200 Episodes Ever, The Third & Fourth Seasons, Bundled Up in Bikini Bottom, Glumly Squidward, The Ultimate SpongeBob Box Set, Nick For the Holidays!, Holidays with SpongeBob 3-DVD Gift Set, The Complete Third Season, Nick Picks Christmas, SpongeBob SquarePants Vol. 4, From the Beginning, Pt.1, First 100 Episodes, and Complete Third Season DVDs.
- This episode is also available on the Christmas Tape.
- "Snowball Effect" was ranked #20 during the Best Day Ever event on November 9–10, 2006.
- While it is Bikini Bottom's second actual snow day after "Christmas Who?," this episode marks SpongeBob and Patrick's second winter-based fun since "Survival of the Idiots."
- This episode marks the fourth appearance of snow, the first three being "Bubble Buddy," "Christmas Who?," and "Survival of the Idiots."
- However, only the second episode takes place during Christmas.
- When Squidward is sitting next to his fireplace, a replica of his head with moose antlers is seen hanging on a plaque on his wall. It is seen again in the SpongeBob SquarePants video game Battle for Bikini Bottom whenever the player goes inside Squidward's house.
- A clip of this episode was shown in a 2006 LEGO SpongeBob commercial.
- There is a online game based on this episode named SpongeBob SnowPants!.
- The scene where SpongeBob batters Patrick with a barrage of snowballs is rarely shown in Indonesia airings due to time constraints.
- In the Arabic dub, this episode is called "معركة الثلوج" (maerakat alththuluj "mar-eh-kat ool-sul-oo-zhey"), which translates to "battle snow."
- Innuendo: A group of fish made giant snowballs for the snow mermaid.
- This is the first time tanks are seen in SpongeBob.
- Patrick's alias "Pink Menace" is a reference to the "Red Menace," a nickname for the Soviet Union that was popular during the Cold War.
- The title is a reference to the phrase of the same name.
- When Squidward speaks about him being attacked in the rear, there is already a wall there and all he does is turn around, laugh, and pat the wall, but he is never seen building it.
- When Mrs. Puff blows the snow off her boatmobile and onto Fred, he pops his head out and yells "Hey!," although his mouth does not move.
- When Squidward demonstrates his fort and how it should be used and Patrick throws snowballs at him, his arm does not move.
- When SpongeBob is first seen with his fort, it is circular and shorter than him, but when the camera returns to SpongeBob, his fort has changed shape and is about as tall as him. Finally, when the camera returns to SpongeBob again, his fort returns to how it originally was.
- When Squidward drops his snowball after he refuses to be on neither Patrick or SpongeBob's side, the mark that he makes in the snow disappears when the camera pans out.
- When the camera shows Patrick laughing after hitting SpongeBob with a snowball, his fort is smooth. Before, it was full of bumps. Also, when Patrick comes upon the barrage of snowballs SpongeBob serves at him, his fort is bumpy again. Also, all the square snowballs he was seen with are gone.
- When a close-up of the DNA strand snowball Patrick made is shown, the sky is light blue instead of gray.
- When Squidward gets frustrated by Patrick's continuous snowball-throwing at him right after he builds his small fort, he attempts to throw back a snowball at Patrick but misses his shot. Instead, the snowball goes inside Squidward's house and puts out his fireplace. This would not have been possible because his house is behind him at the moment he throws the snowball.
- When Squidward builds his fort near the end of the episode, Patrick's house is not seen.
- At the end of the episode, the coral tree that drops snow onto Squidward's head had not been seen throughout the episode.
- Squidward's fireplace is put out by a snowball that is thrown.
- Patrick throwing snowballs at Squidward.