The best time to visit Italy is during the Spring (April to June) and Fall (September to October) seasons.
These months offer pleasant weather conditions and lesser crowds. Northern Italy's weather tends to be colder compared to that of Southern Italy. On the whole, the country's climate is quite mild and predictable. Travellers will be able to find excellent deals on accommodation during this time. It is also an ideal time for sightseeing and outdoor activities, as it is typically dry season and the crowds are also not at their peak. July and August are the hottest months in Italy whereas January is the coldest. November is the wettest month, so you might want to avoid it if you're looking for outdoor activities. Summer tends to get hot and crowded, as well as, expensive, while the winter months are plain wet and cold (especially in the North). Travellers might even want to consider the winter months if they are keen on experiencing a ski resort in the mountainous regions. Once the dates of your trip are finalised, make sure to check the list of holidays and festivals that might coincide with your stay.