What is the recommendation - a microfiber 3/4 raincoat or just a sweater for travel in Venice, Florence and Rome for the first half of October?

I usually check the 10 day forecast before I go and plan accordingly. If light rain is forecast I pack a very small umbrella, heavy rain a raincoat and umbrella, no rain a sweater or polar fleece according to the predicted temperature.

Venice can be cold by the water in October. If you're sheltered by the buildings it's not bad but for those time you're by the canals you'll want something warm. If your raincoat is lightweight and easily packable I'd bring that and maybe a fleece vest for underneath. I'd also throw in a pair of light leather gloves and a skarf. You may not need them but they take up little room and if it's cold and damp you'll be very happy you have them with you.

You'll need some sort of coat, if not necessarily a raincoat.

Both !

October? Definitely take a rain coat AND a sweater.

If you don't need the sweater outdoors you'll need it indoors because most Italian heatings are not turned on before Nov 1.

I have always taken a longish black trench raincoat onto the plane with me. It is very lightweight. It can work as a blanket if I get cold during the flight, which usually happens. It is cut so that I can wear a sweater (even a heavy sweater) or a blazer jacket underneath if necessary. It works with pants and skirts/dresses. I also have a black 3/4 length raincoat but the one time I took it to Italy I found that it didn't work as well as the legs of my pants really got wet when it rained and I was outside a lot so basically I just use that raincoat at home. There is no way I would go to Italy without a raincoat as I have never been there without some rain regardless of the time of the year.

Both - or another type of jacket plus sweater. Definitely a sturdy umbrella and waterproofed shoes.

I'd bring both. It could be cold enough you'd wear them both at the same time.

Land's End has a great water-proof rain jacket that folds into its own pocket so its easy to keep on hand, and a light jacket or light fleece but nothing too heavy or bulky.

Thanks everyone. I will take the black raincoat - it has gone on my last 4 trips and has been great - not too warm but warm when it needed to be. And it is a classic style and plain but good looking so it can be worn anywhere I want to look "presentable". It can be worn over jeans and looks good. Also, the sweater, the leather gloves and I usually take a black fine knit stocking cap which has been wonderful on many cold days. Actually bought it in Ruette when we had the snow in mid-September and it was cold.
It seemed like Sept and Oct were still so warm in Prague, Vienna, Budapest and Italy that I could get by without taking it. But your reminders of how it can get cool, convinced me. Thanks again.

In october, I simply used a sweater and a wind breaker! It's actually a good month to go to Italy... then of course, there are exceptions to what locations you are thinking of going! You will be alright!

Hi,
October weather may be very different from rome to Venice, as Venice is in the northern side of italy it could be windy and rainy, while October in Florence and more in Rome are usually very gentle.

The weather changes now and then and won't stay the same during the whole month. You may just as well meet warm and sunny weather as chilly and rainy days in any of these 3 cities.