The highest temperature of record is 107° F on August 2, 1975, at New Bedford (southern Bristol County) and Chester (northern Worchester County). The lowest of record was -35° F on January 12, 1981, again at Chester.
The average annual temperature in Massachusetts ranges from about 46 degrees Fahrenheit (° F) in the Western Division to 49 in the Central, and to around 50 in the Coastal Division. Averages can vary considerably within these divisions due to elevation, topography and other environmental aspects including urbanization; each can have a significant effect.
Summer temperatures are delightfully comfortable for the most part, and summer averages are quite uniform all across Massachusetts. Long-term averages for July range from 67 to 70° F in the Western Division and in the islands off the coast, from 70 to 74 elsewhere. Hot days, those with maxima of 90° F or higher, generally average from five to 15 per year. The number of 90° F days varies considerably from place to place, but also from year to year.
They can range from only a few days in cool summers to 25 or more in hot summers. Record number of 90 or higher days was experienced during summer of 1983 when 20 - 30 days were observed across the State. The Cape and offshore islands are exceptions, averaging less than one day with a reading of 90 or higher per year. However, on August 2, 1975, even Cape Cod and Nantucket Island reached a record 100° F.
Average temperature data may mask marked differences in day to night changes. Islands and the Cape may have only a daily range of but 10 to 15° F, but inland areas may vary 20 to 30 degrees. The diurnal range can reach 40 to 50° F during cool, dry weather in valleys and marshes. Frost may even be a threat in warmer months in these susceptible areas.
Sometimes visiting a new place can be overwhelming. Where should you go? Everywhere! What should you do? Everything! But if you want to narrow it down a little, this travel guide has some must-sees for each region in Massachusetts, a highway map, plus there are some really pretty photos shared by Massvacation.com.