Character Clues
Character Analysis
Actions
Since there's absolutely no dialogue in The Snowy Day, character's actions become paramount in understanding who they are. Peter is a young boy. Check. But what sort of young boy is he? We get that answer straight from his actions.
The way that Peter experiments with making tracks in the snow (14-17) and seeing what happens when he smacks a snow-laden tree with a stick (19) lets us know that he is curious and inquisitive. He wants to understand the world around him and he's keen, like a budding scientist, to do a few experiments to gain information. And as he sits quietly in the tub replaying his adventures at the end of the day, we see that like a scientist, he's going over his day's discoveries again and again, showing that internal reflection is as much a part of his process as having the experiences themselves.
Peter actions also let us know he is a gentle and peaceful individual. His quiet observations of the snow that has fallen (10), the tall snowbanks (12), and even the snow that falls on his head (20) give us the sense that he is a patient observer. And when he opts out of the snowball fight (22-23) in favor of building "a smiling snowman" and making snow angels, we see that he is content to do his own thing, gently and without drama.
Finally, when Peter discovers that the snowball he set aside for tomorrow has melted, we see that he is, like most young people, a sensitive soul as he heads off to bed feeling very sad (32) and appearing to cry (33).
Likewise, we don't hear any dialogue or internal thoughts from Peter's mother, but we know she is caring, kind, and a solid presence in Peter's life as she listens to his adventures and helps him remove his wet socks (29). Now that's love.
Clothing
The red snowsuit! Now that would be a tough article of clothing to ignore, especially since it tells us a few key things about Peter. For one thing, at a certain age, the fashionability—and practicability—of snowsuits tends to drop off. Dramatically. Unless they're headed out on a full-day snowmobile excursion, teens and adults rarely don bulky, monotone, full-body-covering outfits. So we know from Peter's attire that he is a young child.
The bright red color of Peter's particular snowsuit also indicates his young age and helps to separate him from the "big boys." When Peter witnesses the older kids having a snowball fight, it's apparent that he doesn't belong to that set—at least, not yet. Why? Because of his bright red snowsuit. The big boys are clothed in yellows and greens, and their multi-colored outfits are clearly composed of separate pieces instead of one amorphous suit. True, at times Peter's snowsuit appears that it could be made up of a jacket and pants, but the single color from head to toe gives us the impression that his mittens are probably connected by a string, whereas the big boys can be trusted not to lose theirs.
Peter's mother is also lent a bit of character due to her clothing, but her print dress—believe it or not—has caused controversy. One critic, Nancy Larrick, accused Keats of making Peter's mother a stereotype of African American women by clothing her in such a brightly printed dress, saying that all she lacked was a red bandana (source).
Keats's response to that charge? "The dress is gaily colored as is everything else in the book. […] I wish Miss Larrick would not project upon me the stereotypes in her own mind—or in others" (source).
After Larrick's criticism appeared in the Saturday Review, several people, including Keats, wrote letters to the editor defending the depiction of Peter's mother. But regardless of how you view the dress, it's clear that Peter's mother's clothing has played a large role in the way people interpret her character.
Location
With it's inclusion of traffic lights, sidewalks, and brightly colored buildings, it's clear that The Snowy Day takes place in a city. That makes Peter a child of the city, and that's important. The day to day experiences of people who live in cities, surrounded by architecture and infrastructure, are different from the day to day experiences of people who live in rural settings, surrounded by trees, meadows, or pastures. And knowing that about Peter helps to shape our view of him.
We know, for instance, that Peter must be used to navigating the city on his own—understanding the way the streets and avenues connect his neighborhood to the rest of the city and able to interact with and avoid traffic. This shows him to have, even at his young age, a level of savvy and understanding of his environment that demonstrates his independence. And the fact that Peter lives in an apartment building (35) also lends to his identity as a city dweller, which means he is probably more accustomed to being surrounded by people and activity than kids living in other settings.
Knowing this helps us to appreciate even more Peter's quiet day contemplating the snow. Seeing that he eschews crowds, favoring instead a solo adventure playing, pretending, building, and experiments further helps to define Peter as a gentle, thoughtful, contemplative youth.