the word ‘subtropical’ summons images of palms trees and dolphins, but when new york city was first classified as subtropical the most densely populated city in america did not suddenly turn into a white sandy beach. the changes to the city’s climate and infrastructure have been subtle, but impactful. 

five years ago, the national oceanic and atmospheric administration’s national climate assessment, reclassified new york city from a humid continental climate to a humid subtropical climate. a subtropical climate has summers that are on average above 72 degrees fahrenheit and winters that stay above 27 degrees fahrenheit. 

“it’s kind of like, if you’re a parent, you know your kid is aging and it’s not shocking, right? but if you’re an aunt that hasn’t seen like the kid in five years, you see that and it’s like five inches taller,” said ian olsen, the director of horticulture at the broadway mall association. “it’s very shocking.”

adapting to a new climate

olsen has been in new york for a decade and has worked in the city’s environmental spaces with organizations like the horticultural society of new york and the central park conservancy. as the lead horticulturist for the broadway mall association, olsen wears many hats including assessing how to continue the organization’s beautification and native planting efforts as new york city’s climate changes.

“so we have a situation where the fall is somehow extremely dry, so we have to pay attention. we need more drought-tolerant material. we have to think more about when we plant,” olsen said. 

the broadway mall association and their volunteers are not strangers to trial and error in order to determine which plant life will survive in different outdoor malls across the city. olsen describes wanting to plant ferns throughout new york and being unable to make the plants thrive due to the direct sunlight and high heat of the medians. 

the changes that have happened in new york city’s environmental spaces are indicators of the future, especially since new york city experiences the urban heat island effect which causes the city to get hotter than the surrounding more rural areas due to man-made infrastructure that traps and reflects heat. the urban heat island effect provides a way to see how warming or a change in climate affects the native plant and animal life of a region. 

“the malls are already a space where it’s almost like a simulation of a future, of a potential warming 10 years from now. it gets so hot [in these gardens] that, in a way, it’s almost like a laboratory for seeing what plants will work in general if the climate warms by x amount of degrees over the next however many years,” olsen said about the urban heat island effect. 

what’s next for the big apple’s green spaces?

the possibility that native plants and the current vegetation that grows in the areas the broadway mall association will no longer thrive in new york is not yet a worry for olsen and his team. 

“we won’t use anything that isn’t adapted to climate zone eight,” olsen said. “it’s really a matter of thinking ahead. these plants are adapted to hot but hot, dry areas where, even if we do get that like four or five degrees shift, they’ll be okay.”

five years into the city’s new classification, the effects of the subtropical climate are not theoretical. the city is hot and it is getting hotter for residents. “when i was growing up, i would always have to wear a jacket for trick or treating [on halloween]. whereas now, i could wear a t-shirt and shorts,” said emily johnson, a sustainability management master’s student and a member of the biodiversity club board at columbia university. 

johnson, a student who returned to school to study sustainability after working in the fashion industry, also mentioned she has lived through a multitude of climate events such as the large earthquake in april 2024, the smoke from canada’s wildfires and major subway flooding in the summer of 2025. 

johnson’s background in fashion gives her perspective on how industry and individuals are both affected by new york city’s reclassification. 

“when we think about what products to stock, not even just fashion, but in all industries, you base it off of the weather,” johnson said. “if the temperature changes, they’re going to have to change their buying patterns. so that’s something with fashion too, they’re going to be stocking less jackets in the fall in new york city.”

against the odds, preserving a sense of place

the changes being felt this fall follow a major decision at the federal level in july of 2025 when the trump administration removed and disbanded the national climate assessment. 

kathy jacobs, the director of the university of arizona center for climate adaptation science and solutions and former director of the third national climate assessment, told cnn that the national climate assessment is a heavily reviewed and respected document and as the public discussion around climate change shifts from mitigation to access, real people may be affected by the lack of accessible knowledge around climate change.  

“it’s a sad day for the united states if it is true that the national climate assessment is no longer available. this is evidence of serious tampering with the facts and with people’s access to information, and it actually may increase the risk of people being harmed by climate-related impacts,” jacobs said.

olsen and new yorkers like him are invested in the city’s future, environmentally and physically. changes and reclassifications in new york city provide opportunities for growth and community involvement from like-minded, impassioned individuals who are interested in protecting green spaces in their city. 

“to do this with native plantings is something really unique. what we’re doing is building habitat and kind of creating a bit of a different kind of naturalistic beauty and then hopefully that has the effect of creating a sense of place,” olsen said.