The film opens with talk about snow forming from crystallized water and explaining that a snow day isn't just when school's close, but a day of magic.We're then introduced to Tom Brandston (Chevy Chase) the local weatherman forced to wear a Hawaiian style outfit to promote the warm weather coming in. Tom isn't happy with his job as he works for a station that makes him use gimmicks on camera to improve their low ratings.We're next introduced to Tom's daughter Natalie (Zena Grey) as she hopes to get snow on what were told has been a unusually warm season. As she and her friends Chet (Jade Yorker) and Wayne (Josh Peck) throw snowballs leftover from last year (kept in a cooler) at their principal (Damian Young) a stick in the mud who's a prime target for snowballs during the winter.We're also introduced to Tom's son Hal (Mark Webber), who sits besides the high school pool area with his friends Lane (Schuyler Fisk) and Bill (J. Adam Brown). Hal has a crush on the local popular girl Claire (Emmanuelle Chriqui) as he tells us via voice over. He watches her dive and when sliding along the side of the pool, he falls in and finds her ankle bracelet at the pools bottom. The ankle bracelet containing a whale charm had fallen off when she was diving.Later Hal plans to return it to Claire, but is unable to when her loud jock boyfriend Chuck (David Paetkau) shows up, revealing that he and Claire are on the verge of ending their relationship.Natalie takes Hal's collectible action figures and attempts to play with them, but Hal takes them away from her, claiming he doesn't want her playing with them because he plans to sell them some day. At dinner with their father and younger energetic brother Randy (Connor Matheus), the kids wait for their mother Laura (Jean Smart) to come home, she does arrive, apologizing for being late as she is a workaholic.Later that night, Natalie shakes a snow globe her father has given her, claiming she wished it was that easy to get snow to appear. At the news station, Tom is getting ready to report sunshine all day, when he discovers a snow storm is coming in from his radar.Natalie awakens the next morning to find the entire area has been blanketed in several layers of snow. The radio then announces that all schools are officially closed and a snow day is in effect.Natalie is so excited and plans to use the magic of a snow day to take down her arch enemy, The Snowplowman (Chris Elliott) a local villain who is said to run over kids and plow the streets so efficiently that there has never been a second snow day in years. Natalie enlists Hal's help, but in light of hearing Claire has broken up with Chuck, Hal wants to use the magic of the snow day to return Claire's whale bracelet and profess his love to her.Laura attempts to leave for work, but finds she has been so severely snowed in; she cannot make it into work and must stay home with Randy.Principal Weaver attempts to clean his car off of the snow, but is overwhelmed by an army of kids who are throwing a barrage of snow balls at him. Weaver appears throughout the movie as a running gag, being chased by snow balls as they are pelted at him off screen.Lane meets up with Hal and upon hearing he plans to spend the day winning over Claire; she disapproves and proclaims that love is about finding someone you can stand to be around for more than ten minutes at a time. Hal insists and she follows him.Natalie meets up with Chet and Wayne at their igloo-style snow fort, but Snowplowman appears and after Natalie throws a snowball at him, he maliciously goes off road to plow over their snow fort.Hal and Lane go to Claire's house, where Hal plans to talk to her, but a parade of other suitors has gathered outside her house after hearing about her break up. Chuck arrives and clears them out, attempting to win Claire back. She initially turns the volume on her TV up to drown him out, but caves and lets him inside. Lane hears that the TV station Claire has on is the same one Hal's dad Tom works at, giving Hal an idea.With the record snow fall, Tom is forced to wear a snowman costume to report the weather and is pushed down a scary hill on a sled. With everyone distracted when Tom wipes out, Hal uses the opportunity to introduce himself to Claire on live TV. Recovering from his crash, Tom discovers his rival weatherman Chad (John Schneider) from another station is taking credit for discovering the night's snow storm first.Meanwhile Natalie has her friend Wayne pretend to be dead in the middle of the street, pouring ketchup on him as blood in order to trick Snowplowman. When he leaves the plow to investigate, Natalie sneaks in. She's attacked by his bird Trudy and ends up kidnapping the violent creature, Snowplowman retaliates by grabbing Wayne.Hal and Lane have followed Claire and Chuck to the local skating rink, where Lane distracts the rink's DJ (Iggy Pop) while Hal changes the usually boring music to something more upbeat, much to Chuck's dismay.Next Snowplowman drops by Natalie's house to talk to Laura claiming he's taking kids around in his plow and that she's next in line, claiming Wayne to be his last passenger when she spots him in the plow. When Laura is distracted by Randy, Snowplowman gets a call from Natalie who offers him an exchange, the bird for Wayne and a second snow day, he agrees.Hal's next plan involves Lane going to the local diner where she tells Claire how great a guy Hal is, retelling a story about him. Claire is convinced and follows Lane to the local football field where Hal has carved a giant whale in the snow. Chuck shows up and Hal steals one of his snowmobiles and a chase ensues, Hal gets away.The prisoners are exchanged, but even with his bird back, Snowplowman appears to not be a man of his word as he leaves in his plow back on route to plow the snow.Laura chases after Randy when he escapes outside to play in the snow. Initially she's angry but after Randy throws snowballs at her, she retaliates and finds herself having fun.Natalie is about to give up, but after she imagines what her brother's action figures would tell her if they came to life, she rediscovers her determination for a second snow day.Hal meets up with Lane, but after he shows no signs of giving up, she gets angry admitting she hasn't done what she wants to do for the snow day, when Hal asks what she wants to do, she kisses him and leaves.Tom is reporting on the snow as Old Man Winter, but when his rival Chad appears, Tom proves him a fraud when he's unable to answer basic meteorology questions on air, proving he discovered the storm first.Hal meets up with Claire at the school's pool and she kisses him, but Hal realizes that he was wrong and that he has stronger feelings for Lane. Claire understands.Snowplowman continues to plow the streets, but at the last road, Natalie appears to challenge him. He taunts her but she reveals an army of kids have gathered together to stop him. The kids tie him to a street sign and take his plow to un-plow the snow back onto the roads.Hal journeys to find Lane (dressed in Bill's cloths for some reason) but is attacked by Chuck. A fight ensues, but Hal is saved when Natalie and friends plow Chuck away into a snow bank with the snow plow. Hal is impressed and tells Natalie she can keep his action figures and that he wants to spend the soon to be second snow day with her. They part ways as Hal finds Lane at the local skating rink.Hal apologizes to Lane repeating her line about true love being about finding someone you can stand to be around for ten minutes, and then asks "You got ten minutes?" They kiss.Hal narrates as he recaps everyone's journey throughout the day and the film ends with Principal Weaver making it home, only to find another volley of snowballs come at him from inside his house.