Travel Italy: Vacation Packages, Tips, Tours of Italy

Advice on day trips to Cinque Terre

Would you recommend a day trip from Florence to CT (Cinque Terre) or would be better at least spend the night there?

First, an advice for you and for any foreigners used to write CT as an abbreviation for Cinque Terre.
Such abbreviation does not work in Italy. Better, for Italians that means the initials of car plate for the city of Catania, so if you ask any advice on the Internet boards by writing CT, no Italians will be able to help you. If you like to short the name, you could use 5Terre.

Coming to your question, from Florence to Riomaggiore, one of the villages of Cinque Terre, it take 2 1/2 hours by train, (InterCity, change in LaSpezia or Pisa station; details: see www.trenitalia.com), so you could do it in a day trip.

However I suggest to spend a night there, to be able to enjoy of the several activities Cinque Terre offer you.
Hiking between the five villages, dining in one of the typical restaurants looking down the sea and generally enjoying of the wonderful sights avoiding any rush.