Hello,
I think the biggest thing to safe riding in the rain is good tread on your rear tire, i live in the Cleveland area, we are used to weather changes, if you have good tires, just slow down , if its raining real hard give yourself more room, if it cold 38-48 f you better have gear on to keep you warm and dry, and your rain suit will be worth (edited), if your hands get wet and cold. For me when it start to get like that, i look for a place to hold up., If it get much colder things realy get bad.
Bill