I can explain it, because I studied Meteorologie

Ok this is how freezing rain works,

Rain, when it comes from the sky, is in water form. Sometimes in the upper levels of the stratosphere, it's colder than here on earth. Not often, but sometimes it is. When it's colder higher up, and the rain comes down, it's ice! As soon as the ice gets into warmer air, it turns to water. Ice is actually water...that's frozen!! Ok so the ice warms up as it plummets towards your car, but it doesn't completely thaw. The combo of icey water is also known as freezing rain. Sometimes people refer to freezing rain as "This is the worst weather ever...why can't you drive!?!?!" Well, at least I call it that when I'm driving to work and the mommy or daddy in front of me decides that they want to drive their kid to work, then stop in the middle of the rain, then let their kid out, then hold up traffic, then tell their kid that they left their lunch on their seat, then wave at them, then hold up traffic, then can't get traction on the road and fishtail all over the place, then hold up traffic then make me swear under my breath. Clearly, freezing rain is a direct result of the Fall of Mankind.