Central Park.Although located at about the same latitude as the much warmer European cities of Naples and Madrid, New York has a humid continental climate (Köppen climate classification) resulting from prevailing wind patterns that bring cool air from the interior of the North American continent. New York City has cold winters but the city's coastal position keeps temperatures slightly warmer than inland regions, helping to moderate the amount of snow which averages 25 to 35 inches (63.5 to 88.9 cm) each year.
New York City has a frost-free period lasting an average of 199 days between seasonal freezes. Spring and Autumn in New York City are erratic, and can range from cold and snowy to hot and humid, although they can also be cold or cool and rainy. Summer in New York City is warm and humid, with temperatures of 90 °F (32 °C) or higher recorded on average 18 to 25 days each summer. Though not usually associated with hurricanes, New York City is susceptible to them, notably the 1821 Norfolk and Long Island Hurricane which flooded southern Manhattan, and 1938 Hurricane, which affected New York and killed more than 700 people, most of them in New England. The city's long-term climate patterns have been affected by the Atlantic Multidecadal Oscillation, a 70-year long warming and cooling cycle in the Atlantic that influences the frequency and severity of hurricanes and coastal storms in the region. Many scientists believe, however, that global warming will change this pattern.