having lived in a messy snowy area once upon a time - I would also ask "is there any snow on the route?" You can always use the snow to ride on as it provides traction. I ride on a bike trail the whole way to work and some days its Gorgeous, some days in the winter I do NOT want to know if that was water or ice I just rode over - its just best that way!
As theres only me and my cell phone - I ride pretty much as often as I can! (but I'm down with a cold right now so riding isn't in my forcast! - its a breathing thing ya know?!) Anyway - like everyone else said....if you have an option and it Isn't your only means of transportation - you gotta make the call based on your level of comfortability - after all, in the end it isn't gonna matter if you rode this day or that one or drove!
Life should NOT be a journey to the grave with the intention of arriving safely in an attractive and well preserved body, but rather to skid in sideways, champagne in one hand, strawberries in the other, body thoroughly used up, totally worn out and screaming: "Yeah Baby! What a Ride!"