Maine Weather Statistics Better Than Expected! Maine has three climatic regions: the northern interior zone, comprising roughly the northern half of the state, between Quebec and New Brunswick; the southern interior zone; and the coastal zone. Although all are classified as humid continental, small differences exist among regions. The southern and coastal regions are influenced by air masses from the south and west. North of the land dividing the St. John and Penobscot river basins, air masses moving down the St. Lawrence River basin tend to prevail. The northern zone is both drier and cooler in all four seasons than either of the other zones, while the coastal zone is more moderate in temperature year-round than the other two. Greater Portland Weather Statistics | | |  | |  | | | |  | |  | | | |  | |  | | | |  | | The vast majority of Maine's population live in the southern Coastal Region, which includes Portland and the surrounding areas. There are over 5,000 real estate transactions annually in Cumberland and York counties combined. See: Real Estate Values and Home Sales | | | | As with the rest of Maine, the temperatures in the Greater Portland area are moderated significantly by the sea. Portland's climate is continental, with four distinct seasons. Summers are warm and pleasant, while winters are cold, with snow. Temperatures range between 60°F and 80°F (16°C to 27°C) in summer and between 20°F and 40°F (-7°C to 4°C) in winter. Fall is a popular time to travel to Portland, due to the mild weather and spectacular fall foliage. Maine Relocation: Quality of Life |