These days I'm pretty much an all weather cyclist. I haven't worried too much about rain until recently but this February was the wettest on record over here and I got thoroughly drenched three times. The first time I didn't have any waterproofs with me and, as you said, got really cold. The second time I had some waterproof over-trousers (sorry, pants) with me but I didn't think it was going to be that bad. By the time I realised it was raining really hard and the road had turned in to a river it was too late ... and I got really, really cold AGAIN! By the third time I'd learned my lesson and pulled on my waterproof over-trousers before I left. It made a huge difference. I have a windproof jacket that actually keeps the water out pretty well so the top half of me was fine. My tights, however, are useless in anything other than the slightest shower so the waterproofs made a huge difference. In addition, they covered the tops of my overshoes so I was getting very little water in the shoes. The result was that I arrived home more-or-less warm and dry. I now carry those over-trousers whenever I think it's likely to rain.