Weather in May

That's easy--cool, cold, warm, hot, dry, wet, rainy, sunny.
Seriously, the weather can be anything--normal or abnormal.
Check back for temperatures and conditions for the last five years--that will give you some idea of what to expect.

Of course anecdotal evidence regarding weather may not hold true for this year. I visited in 2013 and found Rome very hot and was glad I had some crop pants. We also had very rainy weather in Florence so I was glad I had a waterproof jacket and an umbrella.

Since that experience, a waterproof jacket is always in my packing list wherever I go, no matter the time of year! Mine is a Marmot Precip so it will fold up into my purse.

Also note that I am from North Idaho and I don't tolerate the heat very well so if you are from a warmer area you might be able to tolerate the heat better than I did.

My grandson and I were in Rome over the last week of May 2015. Temperatures were perfect, mid 70s-low 80s (F.) every day. Most days there were brief, but sometimes enthusiastic, afternoon thundershowers; otherwise blue skies.

Photos here.

The last two weeks of May can have chilly nights, but not really cold, and probably not that chilly in Roma and Firenze. Sometimes rain, but not always throughout an entire day. I like May for visiting Italy.

http://www.holiday-weather.com/rome/averages/

http://www.holiday-weather.com/florence/averages/

Roberto that website is very helpful, thank you! I am glad I asked because I probably would have forgot to bring a rain jacket.

Don't worry about the rain jacket. I never take one to Florence or Rome, because it's too hot to wear it (I go in June every year, when it's even hotter than May).

If you are caught by a rain storm you are covered. There will be hundreds of African vendors with all kind of rain gear who will appear like magic from all over no matter where you are. All you have to do is bargain hard to pay as little as possible for an umbrella or rain poncho. I never pay more than 1 or 2 euro for an umbrella, but my wife (who's not as good at that hard bargaining tactics) often gets taken for 10 euro per umbrella.