New Climate Central Report: NYC High Line Significantly Reduces Impact of Extreme Heat

New data shows the High Line provides a refuge up to 8 degrees cooler than nearby streets, helping mitigate heat waves driven by climate change

Climate Central, in collaboration with Friends of the High Line, released new research today showing that the High Line’s trees and gardens significantly reduce the urban heat island effect and lower temperatures in the immediate area. The data found that air temperatures on the High Line averaged 7.2°F lower than those in the surrounding neighborhoods, and up to 8.1°F cooler compared to the densest nearby cityscape.

Read Climate Central’s report here.

According to the New York City Department of Health and Mental Hygiene, approximately 580 New Yorkers die each year due to hot weather. As heat waves become more frequent and intense, Climate Central’s study highlights the critical role of urban green spaces, like the High Line, in mitigating the urban heat island effect — caused by heat-absorbing and retaining materials like pavement, buildings, and the high density of people. Based on detailed modeling, Climate Central compared conditions along the High Line to those in the surrounding neighborhoods, as well as between different sections of the High Line itself.

Key findings from the report include:

• The High Line reduces NYC’s urban heat island effect by an average 7.2°F compared to surrounding neighborhoods.

• The largest temperature difference – up to 8.1°F cooler – occurs in parts of the park that are surrounded by high population density, including the Sundeck, the Hudson River Overlook, and the Chelsea Grasslands.

• Smaller temperature differences occur in sections of the park with more concrete and rock, although these areas showed at least a 4.4°F temperature decrease compared to surrounding areas.

• On average, neighborhoods adjacent to the High Line experience a nearly 64% reduction in the urban heat island effect.

• While not quantified in this analysis, the shade provided by the High Line also contributes to cooling the area directly beneath the park.

“On average, extreme heat kills more people in the U.S. than any other type of extreme weather. The abundance of asphalt and other manmade materials in cities amplifies theheat–and the risks– in urban areas. As temperatures rise as a result of human-caused climate change, places like the High Line, where people living in a hot urban environment can get some relief, are becoming increasingly important.” said Dr. Kristy Dahl, VP of Science at Climate Central.

“Think of the High Line as a 1.5-mile-long natural air conditioner making the surrounding city healthier and more livable. Climate Central’s detailed analysis shows the park is more than an oasis from the hustle of the city. The more than 1,300 trees and tens of thousands of plants on the High Line create a refuge from extreme heat for tens of thousands of New Yorkers who live nearby,” said Alan van Capelle, Executive Director of Friends of the High Line.

Climate Central used land cover temperature modeling to estimate the urban heat island effect of the New York City neighborhoods surrounding the High Line and the decreased temperatures along the High Line. Based on population density and land cover use–including vegetation as well as building footprints and heights–Climate Central was able to show the temperature difference along the High Line as a result of its extensive green space.

More than 75 million people have visited the High Line since it first opened to the public in June 2009. It has become a model for a network of reclaimed public spaces in cities from Miami to Dallas to Mexico City. The High Line’s botanical-level gardens, art exhibitions, and extensive public programs both on and off the park — which are all free to the public and open 365 days a year — have made it a dynamic oasis, cultural hub, and neighborhood connector for the West Village, Chelsea, and Hell’s Kitchen.

The High Line at a Glance:

• First section of the park opened to the public in June 2009 by the nonprofit conservancy Friends of the High Line

• Approximately 1.5 miles long, extending from Gansevoort Street to 34th Street along the West Side of Manhattan

• More than 15 distinct garden zones house 150,000+ plants and 1,340+ individual trees of 720+ different species

• Friends of the High Line team uses environmentally sustainable practices, prioritizing drought-resistant and climate resilient plants and native species, preserving habitat for wildlife, and avoiding use of chemical pesticides and solvents As a freight rail line, the High Line was in operation from 1934 to 1980

ABOUT CLIMATE CENTRAL

Climate Central is an independent group of scientists and communicators who research and report the facts about our changing climate and how it affects people’s lives. We are a policy-neutral 501(c)(3) nonprofit. Climate Central uses science, data, and technology to generate thousands of local storylines and compelling visuals that make climate change personal and show what can be done about it. We address climate science, sea level rise, extreme weather, energy, and related topics.

ABOUT THE HIGH LINE

The High Line is a public park on the West Side of Manhattan operated, maintained, and funded by the nonprofit conservancy Friends of the High Line. Through our work with communities on and off the High Line, Friends of the High Line is devoted to reimagining public spaces to create connected, healthy neighborhoods and cities.

Built on a historic, elevated rail line, the High Line was always intended to be more than a park. You can walk through the gardens, view art, experience a performance, enjoy food or beverage, or connect with friends and neighbors—all while enjoying a unique perspective of New York City.

Nearly 100% of our annual budget comes through donations. The High Line is owned by the City of New York, and we operate the park under a license agreement with NYC Parks.

For more information, visit thehighline.org and follow us on Facebook, X, Instagram, and TikTok.

@HighLineNYC