New York City Regional Heat Island Initiative

Principal Investigator(s):

Ronald Slosberg, Cynthia Rosenzweig, William D. Solecki

Summary: Project Update [PDF]

The objectives of this project are twofold: Map of Project

To model New York City's urban heat island during heat wave events and assess the effectiveness and economies of three potential heat island mitigation strategies: urban forestation, light surfaces, and living roofs.

To evaluate potential interactive consequences associated with heat islands, with particular attention to land use categorization, electric loads (especially on-peak and in load pockets) and air quality/health impacts (i.e. ozone).

The project used temperature data from three heat waves in the summer of 2002, as well as contemporary temperature data and satellite imaging. An MM5 mesoscale model was used to characterize surface and near-surface air temperatures associated with various land cover and urban morphology types in six case study areas, and the impacts of nine mitigation scenarios were calculated for each case study area as well as for New York City as a whole.

Early analysis indicates that all three mitigation strategies can reduce surface temperatures and, to a lesser degree, near-surface air temperatures, thereby lessening peak electric load during heat waves. Street trees offer the greatest cooling potential per unit area, as well as the greatest overall benefits, while light surfaces offer the greatest overall cooling potential due to the large area available to implement this strategy, and the most favorable benefit/cost ratio. The estimated maximum peak load electric demand reduction from planting street trees in 50% of the available space citywide is 74.29MW. For a 50% implementation of light surfaces citywide the reduction is 200.99MW.


Project Site(s):

  • Metropolitan NY
  • Latitude/Longitude:
  • Region(s): Metropolitan New York
  • County(ies): Bronx, Kings, New York, Queens

Case study areas

surface temp


  • Sampled Medium(Media): air
  • Analyze(s): temperature
  • Sampling Technolog(ies): satellite imaging, weather stations
  • Sampling Frequency: three heat waves in the summer of 2002


  • Total Costs:
  • NYSERDA Costs: $134,010
  • Funding Source(s): NYSERDA, US Forest Service, NYSDEC, NYCDEP
  • Contract Initiated: June-04
  • Final Report: February 2006

Project Website

Related EMEP Projects:


Ronald B. Slosberg
Manager, Energy Solutions Division
Science Applications International Corporation
500 New Karner Road Suite 202
Albany, NY 12205
PH: (518) 452-8800, ext 216
Cynthia Rosenzweig
Goddard Inst. for Space Studies
2880 Broadway
New York, NY 10025
PH: (212) 678-5562
Fax: (212) 678-5648
 Cynthia Rosenzweig
William D. Solecki
Professor and Acting Chair
Department of Geography
Hunter College - City University of New York
New York, New York 10021
PH: (212) 772 4536
Fax: (212) 772 5268
 William D. Solecki
Last Updated: 10/07/2014