With the impending strike in France my flight to Florence out of Paris was changed to a direct to Rome. I arrive now at 6:00 am and need to get to Siena that day. I am looking for the simplest fooproof way to get there. It was suggested I take a train into Rome to the Tiburtina station and then either the Itabus and Flixbus to Siena.
Anyone do that? Is the train to Tiburtina easyish to find at the airport?
Where do I buy bus tickets for the bus? Could use some help as I am traveling alone and leaving tomorrow and hadn't planned this part of the trip.

Also--what is UP with 40 degrees in Siena in the evening! I hadn't planned on a jacket

Thank you!

I'd say the easiest way getting from FCO airport to Roma Tiburtina station with luggage, is to take Leonardo Express from FCO to Roma Termini, and then taxi to Roma Tiburtina station.

If you use Flixbus you can buy tickets on line. www.flixbus.com.

Has anyone done the bus to Siena from the airport? It's 3 hours but I land at 6:00 a.m and the bus leaves at 10:45 am.
https://www.tiemme.tpl.busweb.it/bw/it/risultati

You can easily take the train from the airport to Tiburtina. There is one station at the airport (well signposted) and you can buy a ticket at the automated kiosks or the ticket window. Check trenitalia for timetables and validate your ticket (in the stamping machines) before boarding. If you buy your bus ticket in advance, you risk your flight being late and forfeiting your ticket. You could potentially by your bus ticket online while on the train to Tiburtina. It is normal in Italy to buy your bus ticket before boarding but I don't know whether that applies to Flixbus. There should be somewhere to buy the bus tickets at Tiburtina if you don't wish to buy online. You could have breakfast at Tiburtina before travelling onwards.

Or train to Siena and bus or taxi into town.

Personally I wouldn't hang around the airport for 5hours waiting for a bus. As you are unlikely to be able to get into your accommodation in Siena so early, another alternative would be to stash your luggage at the luggage facility at Termini and go for a morning walk around Rome. An unexpected gift?

Could you change the Paris-Rome flight to Paris-Pisa? Travel from Pisa Airport to Florence SMN is 90 minutes or less, one change. Typically, two departures an hour.

If you're taking the bus from Tiburtina ignore any suggestion to go to Termini.

The FL1 to Tiburtina alternates with the express to Termini at the airport. That means if the waiting train is the express you take the next one.

Once you get to Tiburtina basically follow the crowd outside. You'll see an overpass with traffic lights and a pedestrian crossing. Cross and walk a few minutes.

Once you get to the bus station you'll see various ticket booths. Ask which one is selling tickets for the company you're using. But it wouldn't hurt to buy in advance from home.

I'm not seeing good flight options, so I guess this probably wouldn't work. But if you do find a flight, it would take about 2 hours to get from the Pisa Airport to Siena.