The New York City (NYC) Heat Vulnerability Index (HVI) is a measure of how the risk of heat-related death differs across neighborhoods. Neighborhood risk factors that increase heat- vulnerability in NYC are: less home air conditioning, less green space, hotter surface temperatures, and more residents who are low-income or non-Latinx Black. Differences in these risk factors across neighborhoods are rooted in past and present racism.

HVI is calculated by summing the z scores of the following variables and then assigning the sum to quintile (1-5, with 5 being highest risk of death during heat events):

• Median household income, (American Community Survey 2016-2020 5-year estimates)

• Percent vegetative cover (trees, shrubs or grass) (2017 LiDAR, NYC DOITT)

• Percent of population reported as Non-Hispanic Black on American Community Survey (2016-2020 5-year estimates)

• Average surface temperature data from the NASA’s ECOSTRESS (2020)

• Percent of households reporting Air Conditioning access, Housing ad Vacancy Survey, 2017

How Calculated: Each neighborhood receives a score from 1 (lowest risk) to 5 (highest risk) based on a statistical model that uses social and environmental factors to estimate risk of heat-related death across NYC neighborhoods. A low vulnerability score does not mean no risk. Every neighborhood has residents at risk for heat illness and death. Residents who are at highest heat risk are those who do not have or use air conditioning AND are older or have chronic health conditions or serious mental illnesses.

More info: http://a816-dohbesp.nyc.gov/IndicatorPublic/EPHTPDF/HVI_FAQ.pdf

Measure: Score

Visit: www.nyc.gov/health/heatfor more information about heat illness and how to prevent it.

NYS has its own HVI information.

Source: American Community Survey (2016-2020 5-yr estimates), NASA’s ECOSTRESS (2020), NYC DOITT (2017), United States Census Housing and Vacancy Survey (2017)