New York City has a Cfa subtropical climate, according to the Köppen climate classification. But if the city were not there, the climate could also fall within the humid continental temperature range. According to Köppen that’s Dfa. This is due to the urban heat island effect, which makes the city a few degrees warmer. You notice this especially at night and in winter. Winds blow primarily out of the cold Canadian northwest area during wintertime causing extremely low temperatures. But the city is on average 2 to 3 degrees Celsius or 5 degrees Fahrenheit warmer. It therefore becomes too warm in winter to meet the Köppen Dfa classification for the city. Buildings absorb sunlight during the day and the enormous population and human activities also contribute to the extra heat in the city, making it a man-made climate.
Just north of the city, where fewer people live, we already find the Dfa climate zone. Long Island, east of the city, and the area around the Hudson River north of the city also fall under the Cfa subtropical climate due to their location. The Cfa climate in the city is not only due to human activities. But it certainly contributes to it.
Köppen climate classification
The climate is of course also influenced by the Atlantic Ocean. This and the mainly south westerly winds in summer give it a humid subtropical climate. Coastal breezes temper extreme heat. The Ocean Gulf Stream, east of the city, is a powerful, warm ocean current that flows from the Gulf of Mexico along the east coast of the United States, including the waters of New York City. Although the Gulf Stream does not flow directly through New York, it has a significant impact on the region’s climate and weather. The balance between maritime and continental influences makes New York’s climate less extreme than other inland cities at similar latitudes such as Chicago.
New York City experiences frequent, heavy rainfall. The average annual precipitation is 1250 millimeter or 50 inches. Spring is the wettest season. February is usually the driest month. Every month in the city’s recorded history has reported some rainfall, demonstrating the variability of the climate.
Summers in New York tend to be warm to hot, with temperatures regularly exceeding 30 degrees Celsius or 86 degrees Fahrenheit. The proximity of the ocean can cause high humidity, making it feel more muggy. Due to its coastal location, the city sometimes experiences cooling ocean breezes, but heat waves are also common. The wind in summer time mainly comes from the warm south west.
Winters are cold and windy mainly blowing from the cold north west. Temperatures often drop below freezing, especially in January and February, but the proximity to the ocean and many buildings ensure that temperatures remain slightly milder than further inland. Blizzards are common and the city can receive large amounts of snow when moist air from the Atlantic Ocean collides with colder air from the continent. Winds from Canada can cause extremely low temperatures at this latitude.
Spring and fall are generally mild. Spring starts out cool but warms up quickly, while fall often starts out warm and cools down by December. The city can experience tropical storms in the fall, which lose strength as they move north along the Atlantic coast. Most recently, Hurricane Sandy struck the city on October 29, 2012, causing billions of dollars in damage. It resulted in power outages, severe flooding, and many residents being displaced. Hurricane Sandy originated in the Caribbean Sea and traveled thousands of miles to hit New York hard.
Because there are so many people and buildings in the city, it is warmer than normal in both summer- and winter time. The heat is really noticeable in the subway tunnels. There, the temperature regularly reaches 40 degrees Celsius or 104 degrees fahrenheit. The heat is caused by all kinds of factors, such as the air conditioners in the subway trains., but it can hardly escape from the tunnels when it is also hot outside in the summer time. This makes it very unpleasant to wait for the trains on an overheated platform in the summer. It puts pressure on the city’s quality of life.
The New York City Subway
The highest temperature ever recorded in New York City is still from 1936, when it was 41 degrees Celsius, or 106 degrees Fahrenheit. And the lowest temperature ever recorded was in 1934. -26 degrees Celsius or -15 degrees Fahrenheit.
New York City declared a climate emergency in 2019. Major impacts of climate change for New York City include higher temperatures and heat waves, increased precipitation and heavy rainfall, rising sea levels, and flooding. Heat waves are expected to triple from 2 to 6 times per year, and hot days above 32 degrees Celsius or 90 degrees Fahrenheit are also expected to triple from 18 to 57 days per year. Precipitation is expected to increase by 13%. Meanwhile, sea levels have risen an average of 3 centimeters or 1.2 inches per decade, which will increase the frequency and intensity of flooding.
But still, this man-made climate has it all. The warm Gulf Stream on the east side and the continent on the west side. Where they meet in the middle lies the mighty city of New York.
