Get ready for a day of pure bliss, folks. That's right: it's a snow day.
When Peter wakes up, he looks out his window to discover that it has snowed. Snow covers everything as far as he can see, so after breakfast he puts on his snowsuit and heads out to explore. Peter spends time crunching through the snow, making tracks, watching a snowball fight, exploring his neighborhood, and playing in the snow. At the end of the day, he tells his mother about his adventures. Then he has a hot bath, goes to sleep, and wakes up the next day ready to have more fun in the snow—this time with a friend.
…yep, that's the whole thing. What'd you expect? It's a picture book, after all.