Set on the Bay of Naples, Sorrento has a classically defined Mediterranean climate, with hot, dry summers and cool, wet winters. The four-month stretch from June through September is the warmest time of year—and also high tourist season. August is the hottest month, with highs in the mid-80s. This month is also the busiest, since it's the country's holiday month, when many lodging and restaurant options are either closed or filled with Italian tourists from other parts of the country as they flock to the coasts. Prices for accommodation are predictably higher during this time, too.
You can find much better deals during the shoulder seasons, in the autumn months of September and October and in the spring. In May and September, in particular, the weather is still very mild and pleasant, and there are fewer crowds.
The period from late fall through winter—October to March—is when Sorrento sees the majority of its precipitation. November is the wettest month of the year, with an average of 6.4 inches of rain. That said, it rarely hails or snows; temperatures in November average in the 50s and low 60s. Note that during the winter season, many of the ferry services to popular spots like Capri stop for the off-season.
There are numerous summer music festivals in Sorrento and on surrounding isles like Capri (including the atmospheric Concerti al Tramonto). Sorrento’s Festa di Sant'Anna takes places at the end of July, with parades, fireworks, and lots of good food. To experience the town during a quieter spell, visit at the end of the year to enjoy the festive Christmas décor and fireworks display on Christmas Eve.