Boston Weather In May
Boston May Weather is warm but rarely hot. The normal daily high temperature increases about 5 degrees Fahrenheit from the start of the month until the end of the month. The chance of rain is always present in Boston, but in May the chance of thunderstorms increases.
May is the first month when swimming is usually comfortable, although there's no guarantee. May is one of the best months for golf, running and walking, since the temperatures are still low enough that the humidity will usually not be a negative factor.