Species ranges are expected to shift northward with climate warming. Southern Appalachian Magnolia species have never been recorded in oak-dominated forests on Long Island. This study presents data for the occurrence of Magnolia acuminata, M. macrophylla and M. tripetala, in a few stands at Tiffany Creek Preserve, Oyster Bay Cove, Nassau County, Long Island, New York. A tree core datum suggests that the largest Magnolia acuminata in our oak-dominated stands was established in the 1930's; the population has proliferated in the most recent two decades. The largest population of M. tripetala in our area occurs in a complex of swamp forests dominated by Acer rubrum. We compare the climate Normals of Asheville, NC, in the core area of Magnolia acuminata distribution, with those of Mineola, L. I., NY, near its northeastern limit. We find that the winters (average January temperatures) on Long Island have been colder, and with a longer freezing period than in the mountains and piedmont of North Carolina. This suggests that the microclimate of Oyster Bay Cove, north central (North Shore) Long Island, now resembles that of Asheville, and has become more equable.