The Best time to visit Italy:
July / August:
I have heard many times that people were discouraged from traveling to Italy in August. If you are looking for a place on a beach that might be good advice since they tend to be overcrowded, and most hotels will have no occupancy. This is particularly the case for the weeks immediately before and after the 15th of August as that is the peak of the holiday season for Italians. However, if you are visiting cities like Rome, Florence, Milan - or any city for that matter - July or August are excellent months I would say. In August, most Italians will be on vacation and it is amazingly easy to visit the cities. Traffic is minimal, and parking in Rome, for example, which is normally a stressful and impossible task, becomes easy! Then we must consider the nightlife!
This is a new phenomenon which has emerged in the last 10 years or so. Most cities have all sorts of live entertainment going on every night right on the streets and squares. Rome has its "Estate Romana" (Roman summer) largely financed by the city government, the "comune di Roma", that includes music shows and dancing in many historical places like Castel S. Angelo and near the Coliseum. There is also an annual Latin dancing festival at Fiesta near via Appia. Every night you can choose between 4 or 5 options for places to go where you can dance 'al fresco' - under the stars in the open.
Most tourists do not know about these events: How do you find out when, where, and what is happening? Either ask a local since most of them know, or take a look at the city newspaper (if you can speak Italian of course). These events are all publicized in the "city" section of Roman newspapers. Or you could simply stroll in the streets and squares of the city center, the "centro", and most probably you will stumble on some street entertainment.
One of the delightful things to do in the cities (or even elsewhere in Italy) during July and August is to have dinner in the evening when the temperatures have cooled, in one of the many sidewalk restaurants and trattorias. This also happens to be a favorite pastime of Italians, and you will find dining facilities until late in the night.
During July and August, all of the tourist attractions in the cities and elsewhere remain open. Many of the cities like Rome have organized evening visiting hours in the museums which allow tourists to enjoy the magnificent works of art in a suggestive and relaxed atmosphere. Tickets for the museums may be reserved in advance, or purchased upon arrival at the museum. Usually during July and early August, there are performances of the Rome Opera at the ancient Roman ruins of the "Terme di Caracalla", the baths of Caracalla, near the Coliseum. Tickets for these performances are in high demand and must be purchased well in advance.
For the shopping aficionados August might not be the best month because the big sales are mostly over in July, most retail outlets are closed, and the new autumn collections are not yet displayed. The one drawback to visiting in July and August is the hot, and possibly very hot, summer temperature. The hot climate is particularly prevalent in central and southern Italy, but this year northern Italy (as the rest of Italy and indeed all of Europe) suffered an extraordinary heat wave accompanied by unusually high humidity levels. Normally the summer is hot but rather dry so that the temperatures are quite bearable. This is important, because Italy is generally a non-air conditioned country.
P.S. - Remember to avoid Venice in July and August
June / September:
These are excellent months if you like to go to the seaside - not too crowded - and usually the weather is quite nice. These months are also good for city tourism since it is not too hot. As compared with August the weather is better, but the nightlife (Estate Romana etc ) is gone. However, a number of special events are organized at the beginning of September - for example the magnificent Historic Regatta along the Grand Canal in Venice. To be informed of the special events being organized during this period, or for that matter for any period of the year, you can obtain information from the local tourist offices of the city government. They are either called "Ente per il Turismo" or "Pro Loco".
April / May / October :
I would say these months are perfect for visiting both cities and countryside, in particular Venice (in August the water in the canals can be smelly in Venice…). Easter often occurs in April so check your calendar because late booking of flights might be difficult.
November to March:
During this period, it really depends on your luck. You might find cold, rain, and awful weather or possibly pleasant and dry conditions, particularly if you keep south of Florence. These are good months to visit the deep south, like Sicily. The advantage that this period offers is mainly CHEAP AIRLINE FLIGHTS.
Unlike the U.S., Easter is a very important holiday in Italy. Immediately following Easter Sunday, "Pasqua", is Easter Monday, "Pasquetta". The long weekend encourages people to extend their days of vacation, possibly to the following weekend. Traffic can be pretty intensive at the beginning and end of the period.
Reserve your flight well in advance since they fill up pretty quickly in this period - also expect to pay a premium. Family is of course the Christmas theme. In recent years all of the major cities and also smaller centers have Christmas decorations in the streets (particularly around the main shopping areas).
If you are in Italy for Christmas you might as well stay for New Year … New Year is also considered a major holiday in Italy. People usually take off from work both the 31st and the 1st … to recover. Dancing and being with friends is the New Year's theme. A relatively new development is the organization of big New Year's parties or gatherings in the main squares of big cities where anyone is free to participate. In smaller centers, various types of local celebrations are organized. For example in small towns in Tuscany, like Pienza, a huge fire is built in the central square and it burns all night long and into the new day so that the villagers and visitors can gather around, speak, and joke and celebrate the new year together.
If you are there for Christmas and the New Year, you might consider staying on until the Epiphany, which is on January 6. This is the date that finally closes the Christmas season and it is celebrated mostly for children who receive gifts from the old benevolent witch, the "befana". In the squares of many of the main cities, like Piazza Navona in Rome, are countless stalls exhibiting all kinds of toys which really give your children the "gimmees".
Of course if you are going to Italy to ski …forget all of the above. The best period is usually from late December to the end of March. Afterward the rates for hotel and ski passes are lower, but you are not sure to find really good snow conditions.
See also Italy Average Weather
By Paolo Nascimbeni