Can you leave your rain gauge outside in winter? Yes, you can. As soon as the snow melts, your rain gauge will be back doing what it does best—measuring rain. Glass rain gauge beakers can break during even short freezes, but the World's Coolest Rain Gauge™ can be left outside all winter.
The solid copper flute will weather to a graceful patina over time, but it will not rust, rot or crack. The polycarbonate measurement tube is unbreakable and can withstand years of frigid, snowy winters.
I recommend bringing the gauge indoors in the winter to protect against snow plow mishaps and lost measurement tubes, but as you can see, I don't take my own advice.