New England is unpredictable and becomes very cold in the
winter and is prone to mild bouts of humidity in the summer. The vast majority
of tourism in Boston takes place in the summer, from late May through late
September, when the weather is ideal and the most attractions are open. Boston
summers are quite comfortable, with sunshine 60-65% of the time and and highs
in the mid 70s to low 80s F (mid to upper 20s C).
When the heat does start, there are some beaches within the
city, and many beaches outside of it, for swimming. The Standells classic
"Dirty Water"