Köppen Climate Classification

Climate covers everything from averages to extremes of different meteorological variables, such as temperature and precipitation. Köppen climate classifications give information about these different variables.

Despite being the 7th smallest state, Massachusetts has four unique climatic zones across an area of 10,555 square miles.

Humid Subtropical (Cfa): This climate zone has warm-to-hot summers with cold-to-mild winters. The average temperature of the coldest month is below 64°F (17.8°C) and above 27°F (-2.8°C). There is usually no dry season with this classification, and the rainfall is highly variable year-round.

Subtropical Highlands (Cfb): This climatic zone is a subset of the oceanic climates that exist in elevated portions of the world located within the subtropics. It generally features cool summers and winters, and small shifts in the annual temperature. The higher altitudes mean the climate of these higher altitude regions share similar characteristics to oceanic climates but tend to have drier weather during certain seasons.

Humid Continental (Dfa): This climate zone has warm-to-hot (humid) summers with cold (sometimes bitterly cold) winters. The average temperature of the warmest month is 71.6°F (22°C). There is usually no dry season with this classification, and the rainfall is evenly distributed throughout the year.

Humid Continental (Dfb): This climate zone has an average temperature in the warmest month below 72°F (22°C) and the average temperatures in the coldest month are generally far below the 27°F (-3°C). Summer high temperatures in this zone average between 70-82°F (21-28°C) during the daytime. There is only about a 3-5 month frost-free period and heat waves rarely last over a week.

Let’s explore the influences on the climatic zones of Massachusetts.