Riding in the rain can be fun if you are properly equipped and ride smoothly (as covered above) and extra carefully.
I like Rain-X on my face shield. My wet gloves have a squeegee on the left forefinger for clearing any junk on the shield.
Most street riding from 30-95 degrees F, I wear my Aerostich one piece suit (with all optional hard armor). It is easy on, easy off; and waterproof for about 1 hour in hard rain. If you waterproof it with a good spray, it can last much longer. In the summer I have soaked it in water when I've gotten too hot on long summer rides and that helps a lot
. I've found myself wishing (and sometimes getting
) rain on long summer rides
Sidi Vertigo Mega Gore-Tex Boots keep my feet dry. I like those a lot.
Other drivers will have a harder time seeing you in the rain, and they don't notice you in the best of circumstances; so in the rain it's really bad.
More random stuff (gravel, mud, ...) will get splashed up on, or washed into the road. Normally safe curves are more likely than normal to hold hidden surprises.
Tire tread depth, that hardly matters on dry roads, matters a LOT on wet roads.