There are festivals year round, so here's a list in chronological order. Please remember that the specific dates might vary slightly from year to year, but usually are around the same time.
ANTEPRIME FAIRSThese are the fairs generally organised during February and are "anteprime" so early presentations of the new vintages that are going to be released on the market in the current year. These are strictly wine related fairs held usually inside the villages in halls or heated tents.
Usually journalists and the like will be invited on a first exclusive day, after which the fairs are open to people of the trade. You must get an invitation to participate. If you are serious wino, you may consider mingling in during one of these fairs. Invitations can be obtained either from participating wineries or through the local Consorzio that is also the organiser of the event.
The dates for 2015 are not released yet, but you can contact the different Consorzio for more info:
Chianti Classico è in Florence in Stazione Leopolda: Consorzio del Chianti Classico
Anteprima della Vernaccia in San Gimignano: Consorzio della Vernaccia di San Gimignano
Benvenuto Brunello in Montalcino: Consorzio del Brunello di Montalcino
Anteprima del Vino Nobile in Montepulciano: Consorzio del Vino Nobile di Montepulciano
Anteprima dei Vini della Costa Toscana in Lucca: Associazione grandi cru della costa Toscana
DATES FOR TUSCAN WINE FESTIVALS & EVENTSThe village festivals with the wine theme are for the general public with wineries surrounding just one single village. Not all villages will have one, but they are followed quite popularly even by great wineries as it is an event to gather in festive circumstances. These fairs tend to be in the open so around the streets or piazzas of a village. Often there'll be music and other street stalls and perhaps even dinners organised with wine tastings.
Costs of these fairs may vary, but usually 10-15 euro will get you a glass that you can use to sample as many wines as you like for the entire duration of the fair. And you get to keep the glass as a souvenir!
Mid May Wine Town in Florence is a big wine event that spreads out in different locations around Florence. Check the program online that changes from year to year.
Last Sunday of May: Cantine Aperte - special Sunday where a lot of wineries will be open to the public and do tours of their estates, accompanied often by foods and music.
First week-end: Radda nel Bicchiere is a 2-day wine festival that takes place in the main street and Piazza of Radda in Chianti and will feature wineries from around the village only.
Second week-end: Pentecoste a Castellina is another 2-day wine festival with the Chianti Classico wineries surrounding the village. They will set up their stands through the characteristic Via delle Volta (a vaulted medieval road).
Third week-end: Bio Pride in Gaiole in Chianti (in the old Ricasoli cellars). This is a new festival for organic wine makers and produce which to my knowledge is new from 2014. We'll see how it is!
From June-July: Wednesdays with Nobile in Montepulciano's Piazza Grande featuring a couple of different wineries every Wednesday at 6 pm with a local food.
From June-July: Melodia del Vino - classical concerts in Tuscany's big famous wineries.
Calici di Stelle is on August 10, the day of San Lorenzo and is an evening tasting which happens in a few different villages (I haven't found a complete list of events). The idea is to drink local wines in the evening when it gets cool enough to actually drink wine, and to watch the stars and to dig the local culture.
Second week-end: Chianti Classico Expo in Greve in Chianti is a festival over 3 days: Friday, Saturday & Sunday in the central Piazza del Mercato.
Third week-end: Vino al Vino in Panzano in Chianti is an intense week-end of excellent wines in the very small piazza in Panzano.
September is also harvest time, and some wineries will let you participate in the grape harvest. Check out this list of places that would welcome you.
VinItaly is Italy's largest wine fair that takes place in Verona in spring (in 2015 it'll be from the 22nd to the 25th of March). It's really a trade show, but it's open to anyone interested in visiting it. This is a great occasion to taste wines from Italy's 20 different regions. Each region has a space dedicated to its producers and there are literally thousands of wineries there pouring their wines and ready for a little chat. You can get free tickets if you have friends who have a winery who's going to the show, so ask around, or you can pay the ticket to enter (it's around a 50 euro ticket per day!) www.vinitaly.com
NOT JUST WINE...FOOD!
In March Taste in Florence is a big food fair at the Stazione Leopoldo that involves large parts of the city with special food related events during a week-end. This is a great time to come if you are a foodie and want to dive into marvellous foods of Tuscany and Italy.
During the year Tuscany has plenty of food festivals that are called Sagre. They usually have a specific food theme - could be anything from something that's in season, is particular to the area or just for the sake of having a village feast. Here's a list in Italian of the ones going on during the month.
And remember that you can learn about Tuscany's wines and foods in English every day in Florence or Siena at the Tuscan Wine School!