New England's coastal weather is famously whimsical: A flowery spring day could bring rain showers, and a hot and sticky midsummer afternoon could suddenly turn blustery. In autumn, the weather tends to be pleasant and cool, with temperatures dipping at night. Expect summer lows in the 50s-60s F/low teens C, highs in the 70s-80s F/20s C. It is a rare day when temperatures go above 90 F/32 C in the summer, and gentle breezes tend to break the heat by early evening. In September and October, lows may reach the 40s F/4-9 C, and highs are in the 60s-70s F/teens-low 20s C. January and February are the coldest months, with temperatures averaging 30 F/-1 C. Remember that the beach can feel much cooler than inland areas.
Of course, gale-force winds can also erupt—these usually occur during the peak of hurricane season, late August-September. When rain comes, it can be heavy and torrential. Winter snows tend to be limited, and by late March, accumulated snow disappears quickly. However, given the unpredictability of New England's weather, snowstorms have taken place as early as October and as late as April and May.
The best times to visit are either during the height of the tourist season (June-September) or September-December. Late spring can also be a lovely time to visit, when gardens and flowering trees are in bloom.