Climate of New York - Temperatures

Temperatures

See also: Cold air damming and Urban heat island

The annual average temperature across the state ranges from around 39 °F (4 °C) across northeast sections of the state to near 53 °F (12 °C) across Long Island. New York has a humid continental climate (Koppen Dfa in some central and southern lowlands and the Hudson Valley south of Albany and in some isolated pockets of Western New York, but otherwise Dfb over the rest of the upstate). Weather in New York is heavily influenced by two continental air masses: a warm, humid one from the southwest and a cold, dry one from the northwest.

A cool, humid airflow from the North Atlantic has a noticeable effect on weather in the state. When a cool high-pressure area wedges in east of the Appalachians, a cold air damming situation develops which causes a persistent cloud deck with associated precipitation which linger across the region for prolonged periods of time. Temperature differences between the warmer coast and inland sections east of the terrain can exceed 36 degrees Fahrenheit (20 degrees Celsius), with rain near the coast and frozen precipitation, such as sleet and freezing rain, falling inland. Two-thirds of such events occur between October and April, with summer events preceded by the passage of a backdoor cold front, which moves from northeast to southwest.

New York City is an urban heat island, with temperatures 5-7 degrees Fahrenheit (3-4 degrees Celsius) warmer overnight than surrounding areas. In an effort to fight this warming, roofs of buildings are being painted white across the city in an effort to increase the reflection of solar energy, or albedo.