According to the Köppen climate classification, New York City features a humid subtropical climate (Cfa). The city experiences long, hot, humid summers with frequent late day thundershowers, and moderately cold winters, with snow or a mix of snow and rain on occasion. New York's location in the southernmost part of the state, its proximity to the Atlantic Ocean, and its large population (and, consequentially, a strong urban heat island effect) all shape its climate. Thus, New York City has a marginal humid subtropical climate, in contrast to the rest of the state, which features a humid continental climate.
Meteorological records have been kept at Central Park since 1821, although the station was relocated to a different part of the park on January 1, 1920. There are also other weather stations in the area including one at LaGuardia Airport, beginning in 1940, and at JFK Airport, beginning in 1948. However, due to Central Park's long records and central location, it is often considered the main station for the city. Hence, all records unless otherwise stated will be for this station.
The highest temperature ever observed in Central Park is on July 9, 1936 - although LaGuardia reported on July 3, 1966, and the lowest is on February 9, 1934. The lowest daily maximum is on December 30, 1917. The highest daily minimum at Central Park is on July 2, 1903.
The averages 42 to 49 inches of precipitation annually, with snowfall averaging per year but is highly variable between winter seasons. The city can also be prone to strong winds, being a coastal location it is exposed to the Atlantic. Hurricane Hazel in 1954 produced a wind gust of 83 mph, while a gust of being reported on December 2, 1974. Governors Island, Manhattan, in New York Harbor, is planned to host a US$1 billion research and education center poised to make New York City the global leader in addressing the climate crisis.
New York City falls under different climate types depending on the climate classification system used. However, the Köppen climate classification system is the most widely used climate classification scheme, in which New York City falls under the humid subtropical zone.
In the Holdridge life zones system, having a mean annual biotemperature above and mean annual precipitation above , New York City features a warm temperate moist forest climate. By the Trewartha classification, the city is defined as having a Temperate climate (Dc). Annually, the city averages 234 days with at least some sunshine. The USDA plant hardiness zones are 7a and 7b. Most of the city is found in 7b, with forested areas and parks being in 7a, as shown in Staten Island and suburban areas. The city also has some small densely populated areas in 8a, like around LaGuardia airport.
The city's annual temperature profile consists of a warm to hot season from May through October, and a cool to cold period from November through April. However, due to its proximity to the Atlantic Ocean, these swings are less significant than areas further inland. The Atlantic serves as a moderator of the temperature meaning the city is milder than areas inland during the winter and cooler during the summer. All extremes are for the Central Park station.
In an average year, the temperature will usually be between and with temperatures greatly exceeding these values being uncommon. Temperatures at or above and below are very rare, with the last occurrences being July 18, 2012 and February 14, 2016, respectively.
New York City averages annually. Spring is the wettest season and February is the driest month. Every single month in the city's recorded history has reported some rainfall, showing the variability of the climate. On occasion, tropical systems can drop heavy rainfall. The record for days without rain, is 36 consecutive days, between October 10 and November 13, 1924. The most rainfall in 24 hours was on September 23, 1882.
Annually, most snow in New York City occurs from December through late March. Snowfall averages per year but is highly variable between winter seasons. The most snowfall was on January 23, 2016.
The city generally experiences sunny conditions. As a result of New York City's latitude, , it is not subject to the extremes of daylight that places much farther north see. However, it is far north enough for there to be a moderate change of possible daylight hours throughout the year.
New York City can occasionally experience strong winds, like many coastal locations. Tropical cyclones or intense oceanic storms bring the strongest winds. The strongest gust in Central Park, of , occurred on December 2, 1974, however, a station at The Battery reported a gust of on October 14, 1954, during Hurricane Hazel. Most recently Hurricane Sandy struck the city on October 29, 2012, causing billions of dollars in damage. It resulted in loss of power, severe flooding and many residents being displaced.
Being a coastal city, New York City is expected to experience significant effects from rising sea levels. Predictions that the sea level will rise by as much as by 2100 have prompted the city's mayor to invest $10 billion into keeping the city safe. The city is also expected to become more susceptible to storm surges and flooding, meaning events like Hurricane Sandy's impacts will become more likely in the future.
The temperature in New York City has generally increased steadily over the last 150 years and this trend is expected to continue due to anthropogenic warming. By 2080, it is predicted that the climate of the city will be similar to coastal South Carolina. The mean temperature has risen by since the 1970s and this warming is expected to accelerate in the coming decades.
Precipitation in the city has significantly increased since 2000; both rainfall and snowfall have risen, but snowfall has increased much more significantly. However, it is argued that such trends, being so recent, make it impossible to predict whether such increases will continue or become steadier.