Your opinions please.

Any particular area of Italy you will be?

Another kind of meltdown to consider - this is a hell summer for travelers to Europe. Airports are frequently in disaster mode. That should be reason enough to push until it's cooler. And be aware that depending on where you are in Italy, since it's a very long country, the weather will differ considerably. October in Milan can be downright chilly.

It’s really really hard to predict the weather. We were just there, May 11-21. The week before or so it was chilly, rainy and cool. After we left all those scorching hot days started like you mentioned. The 10 days we were there it ranged from 78-81, with only 86 and one 87 in Rome, low humidity. Perfect.

I will say it’s still spring, so your chances of rain are more than the fall , and as you know it heats up as the month progresses. Another thing to consider…my allergies were awful there.

I think late September/early October will always be my choice. It’s just hard to know.

I was there middle of September 2015 and it was perfect. My friend was there exactly the year before same time and it was really hot.

Joe- we start in Venice 3 nights, then Florence 3 nights, Tuscany towns for 8 nights and Rome 3 nights.

The weather is unpredictable and crazy, but if there is a month when you have the best chance of finding the perfect balance of warm but not hot temperatures, sunny, springtime landscape, long daylight, that month is definitely May. I think it's the best time to visit Italy, if you don't mind the tourists since between April 1 and October 31, tourist season is at its peak.

As mentioned there is a chance that it will be an odd May, like this past May 2022, with scorching temperatures, or maybe like 2019, when May was unseasonably cool and rainy. However generally temperatures in May are not scorching hot.

The only time temperatures may go above 82F (28C) is in the last week or at most the last 10 days of the month. So if you want to minimize your chances of finding temperatures above 82F (28C), avoid the last week of May, and you are set. In your case, you might find hot temperatures only in the last few days of your trip. If you happen to be in Rome, that is not too bad. Rome gets nice breezes in the evenings. The important thing is to avoid Florence when it's hot. Florence sits in a hole surrounded by hills and it becomes a fire pit when it's hot.

Below are the temperatures archives for May (Maggio) in Florence. You can check any year of the past (and also any location in Italy). You'll see that high temperatures above 85F practically never happen in the first 3 weeks of May.

https://www.ilmeteo.it/portale/archivio-meteo/Firenze/2022/Maggio

End of September/October may or may not have cooler temperatures than May (no guarantees since the first 20 days of September is often hot with temperatures above 85F), and October is also rainier while daylight is not as long. So choose your poison.

I know you plan to go a few weeks earlier, but I decided to check this week's temps for Florence. They are forecast to by 95 degrees! We were in Rome one August and it was 105. This was before air conditioning.

I don't know when the season starts to taper off. I think Roberto had a good point. Daylight will certainly be longer in May than October. That may factor into your decision.

We went to Tuscany a few years ago right before Christmas. Mornings were cool but warmed up into the 60s by afternoon. Days were shorter but led to some amazing photos at dusk.

Next time we go, we want to schedule around the Fall festivals and harvest season. It think it would be a lovely time to visit. BTW, we are slightly older than you. If you are in relatively good health, you should be OK. We just returned from Chicago where my wife attended a conference. We were in a good location and could walk to museums and restaurants. We averaged walking 7 miles a day.

Hot May temps this year does not necessarily mean hot May temps next year. Traveling in the Spring and Fall off-seasons has both pros and cons. Pros are usually lower prices and fewer crowds, cons are that the weather in these seasons is 'in flux' and, in most countries, can go either way - cool and wet, hot and dry, or any combination thereof. I'd probably still go in May as planned.

After reading all your responses, I’m going to keep the trip as planned and hope for the best. You presented reasons for both times which is helpful. Maybe I’ll need to do a return trip in the fall! We are both healthy and will just have to adjust our days according to the heat. That’s interesting about why Florence gets so hot. Thank you for all your advice, it makes me feel better.
I do have one other question:
How long of a layover do I need in CDG?

I do have one other question:
How long of a layover do I need in CDG?

Five days. That will give you a chance to pop into town.

I hope someone can give you a serious answer. I don't know if Covid is taking longer. I think it took us a good hour to go through customs when we flew into Paris. I'm thinking a minimum of two hours with three to be on the safe side. We've flown into Amsterdam then taken a connecting flight to Basel, but not flown into Paris an connected to another flight.

Why not go in April? Weather will still be nice but less chance of extreme heat.

How long of a layover do I need in CDG?

Are you looking at a DIY multi ticket change, or a single ticket through the airline?

When we travel in spring it is usually from early April through early May. You might have more chilly and wet days, but you typically avoid the heat. When travelling in the fall we go from mid-Sept to mid-Oct. Temperatures are relatively moderate then. Cool, clear mornings in early October are typical.

Have fun!

I’m looking at one ticket.
I did go to Italy in April my first time and it was nice. Just a light jacket required, no rain that I can remember. However, this April there was so much rain.
I had entered April 2023 flight dates just to browse and found that a round trip to Rome was cheaper. And, we would be able to connect in the US easier with only one layover, which makes me happy. That said, our trip starts in Venice so that looks like it would be a 4 hour train ride from Rome to Venice. If we departed one day earlier to Rome than planned, we could take the train to Venice and still start our trip there. Thoughts? Just juggling ideas.
Of course, I’ll keep an eye on things as time goes by. My friend is 6’2”, so we are hoping for seats in the emergency row so she will have more legroom.

If flying in/out of Rome looks cheaper, be sure you factor in all your costs when comparing it to flying - Home-VCE, FCO-Home as a multi-city ( open jaw ) booking.

If you have to fly in a day earlier than you would otherwise travel there is the hotel cost plus the train fare to add on to the Rome r/t fare. Also your time/convenience has value as well. Do as you think best, but be sure to add up everything and not just the airfare when calculating the cost.

Happy travels

No matter what, book a hotel with good AC. Be sure when you book, that you check to see that the hotel offers AC.

We have been at all different times of the year and swore never again in the summer. It was just unpleasant. Our personal preference is fall or spring. The days may be shorter, but the weather isn't blistering.

September is my favorite time in Italy.

This year I went end of May before school is out as I have done before. Rained in Venice -
scorching hot in Florence and Rome. It was hot and crowded- but I was in Italy and loved every minute of it. Missed Italy and traveling so much. This was my first Trip back since 2019.

I rescheduled last year waiting for that perfect time and realize that just may never come.

I will say, Italy was very very busy! more than I can remember during May.

JR just said what I was thinking. Be thoughtful in your choices for accommodations and make sure you have Air Conditioning.

PS quite fun to have a "JR" from Texas on the forum.....

I don’t think I want to fly into Rome for all the reasons you raised, plus a 4 hour train ride after flying all night. have chosen Air BNBs in each location and all but one says AC (Montepulciano), so I need to give that some thought. Can we use it in May? Isn’t there some law about when A/C can be used?

OP: you also have to check that the AC listed in your accommodations is not just a portable fan.
If you look at photos in the listings, you should see white metal "boxes", about 8 inches high and about 3 to 4 feet long, mounted on the wall above doors and/ or windows in the rooms.
These are the AC /heating units.
Make sure to look carefully for these in the photos if you really want proper AC, especially in the bedrooms.
Yes, there is a new rule for AC regarding the settings to save power.....perhaps someone else here can provide more info about it?

We have visited Italy in April, June, July and October. To me, May would not be a problem, but I live in South Georgia and Italy would probably be cooler than here.

I am 74 and my wife and I would think nothing of taking the train after an intercontinental flight. Trains are comfortable with roomy seating.
https://weather-and-climate.com/averages-Italy-May

I went to Rome and Umbria in October 2019 and the weather was hot then! I was really surprised. Went back to Italy last month (May), and yes, in the 90s in Rome -- but cooler on the coast. Also surprised by how crowded it was everywhere in the fall, pre-pandemic. I think you could encounter warm weather in both May and Sept, so not sure I would change your timeline.

Geovagriffith: Thanks for you input. It’s more about the time it would take to land, transfer to the train and then the actual train ride. It may be our best option for connecting with each other in the US and then going directly to Rome. R also, Rome flights arrive earlier than Venice flights.
Claudia: it sounds like there are crowds in the spring AND fall from what I’m hearing.

Ha, you mentioned an A/C law and that reminded me of Milan. We were sitting in our room freezing, I believe it was October, my wife insisted I call downstairs to see about heat and they said, Well there's no heat yet we haven't turned it on for the season.

Also beware that in addition to heat, Firenza can have a real problem with mosquitos. Ask me how I know (ouch).

Is it possible to reverse your itinerary? That way you’d be heading north as it warms. May is really not that hot as compared to June-August.

Some of the air bnbs we booked have a/c, but I don’t think the Montepulciano one does. Do we chance it or cancel and find another? It’s so charming. 😁
Changing the order of the trip is not an option because we have all our places booked, but it was a good thought.

We usually travel to Italy early October and have always had fabulous weather, sunny but mild. Towards the end of the month it starts to get chilly, which is just about the time we go home. You exchange the long Summer days with heat for shorter days in the fall with mild weather. Last trip we went in the summer, never again...it was so hot.