Climate[edit]
Eastern hemlock is generally confined to areas with cool and humid climates. Precipitation in the areas where it grows is typically 740 mm (29 inches) to more than 1270 mm (50 inches) per year. The lower number is more typical of northern forests that receive heavy snowfall; the higher number is common in southerly areas with high summer rainfall. Near the Atlantic coast and in the southern Appalachians where the trees often reach their greatest heights, annual rainfall often exceeds 1520 mm (60 inches). In the north of its range, the temperatures in January average -12°C, while in July they average only 16°C. In these areas, the frost-free season can last fewer than 80 days. In contrast, the southern end of the range experiences up to 200 days without frost and January temperatures as high as 6°C.[9]