Snow starts the same way rain does: the cloud-line on top is the same sky that rains in 雨, a character you already know. Beneath it, old dictionaries explain the second half as a hand gripping a broom — as if the very shape of the word remembers that the first thing you do once the snow stops falling is sweep it from the step.
A piece of culture
A poem in the snow One snowy day around 376 CE, the statesman Xie An asked his family gathered indoors, "What does the flying snow resemble?" His nephew answered, "Scattering salt in the air." His young niece, Xie Daoyun, offered instead, "More like willow catkins lifted by the wind." Her image was so much livelier that it was recorded for the ages in the Shishuo Xinyu (A New Account of the Tales of the World), and "talent for willow catkins" (咏絮之才) became, and remains, the classical compliment for a brilliant woman writer.
Use it in a real word
下雪
xiàxuě · haa6 syut3
to snow — literally "down snow"; you already know 下