Hyannis, MA Climate

Climate Insight: Hyannis, MA

In Hyannis, Massachusetts, the NOAA 1991–2020 climate normals put the annual average temperature at 50°F, ranging from a mean daily high of 58°F to a mean daily low of 43°F. July is typically the warmest month of the year, while January is the coldest. As thirty-year averages computed from station USC00193821, these numbers smooth out year-to-year noise into a working baseline for a typical month.

Rainfall (and snow, where it falls) shapes day-to-day life here as much as temperature does. Hyannis sees about 45.7 inches of precipitation a year, with 21.5 inches typically falling as snow. The frost-free season averages 197 days, which directly shapes the planting calendar and growing potential for the area, with the last spring freeze near April 16 and the first fall freeze near October 30. On the energy side, 5,819 heating degree days and 494 cooling degree days tell the story of how often furnaces and air conditioners run during a normal year.

On PlainClimate's composite comfort index, Hyannis scores 63/100 (Good), a blended measure that weighs temperature mildness, precipitation moderation, and extreme-weather frequency against one another. The monthly tables above are the practical planning tool: mild highs and lows land in the shoulder seasons, July-driven heat peaks in summer, and January-driven cold sets in over deep winter. These are thirty-year averages, not a forecast - any single year can run warmer, wetter, drier, or cooler than the normal.