What to wear in May

Plan for rain, bring a lightweight rain coat with a hood. We travel to Italy in May most of the time, the last few times it's been really warm, that being said, Europe is fairly cold and wet right now. I noticed that it rained in Rome today... Pack light, but do bring a sweater to layer. ( I usually bring a cotton one that buttons up the front, easy to take on and off, or wear over my shoulders for warmth) Don't expect you need a winter coat by 3rd week of May. Rome is warmer than the northern cities. I'd suggest capri pants, perhaps a skirt if you are comfortable wearing one. At least one long sleeve shirt (you can push or roll the sleeves up if it gets warm) You can Google the weather history in Rome and get an idea of the average temp and rain. I always travel with one pair of sandals and one pair of closed toed shoes (Puma walking shoes, European looking, comfortable and more stylish than "running" shoes)

Nobody knows. Use weather underground for 15 years worth of statistics but past performance is no indication of future results.

Of all of my trips to Italy in May, it has been pretty warm, hot in Rome even. My last trip there was May of 2011, and it was still hot. I usually take a light windshirt to throw on over whatever shirt I'm wearing, if necessary. I've never been cold in Italy, but 2012 is a weird year, so who knows.
I wouldn't bring anything too heavy though, as it will likely be unnecessary weight. If you get over there, and you're wrong, then buy a "I stood in line for 3 hours at the Vatican Museum" sweatshirt... Have fun!

Have been in Rome & florence that last 8 days & National Weather service hasn't got it right one day. It poured all night last night in Florence & was supposed to rain & thunderstorm all day today. we had a gorgeous day & I'm currently sitting on my balcony with wine & snacks in tee shirt. Follow the other instructions of packing light with layers. Have a little umbrella or poncho & you should be fine.

Thank you everyone for the great info! I hope we don't get too much rain that would really stink! Thanks.