Heat Impacts in Nashville

Understanding Nashville Heat StoryMap

Metro Nashville is working to educate Nashvillians on the concept of extreme heat. In April 2023, the Mayor’s Office launched a StoryMap, Understanding Nashville Heat. The StoryMap and content that follows on this page explain more about extreme heat events, factors that may increase Nashvillians risk to heat, and efforts to understand its impact on our City.

Nashville Heat StoryMap

Nashville’s Heat Mapping Campaign

In Summer 2022, local experts, nonprofits, and researchers teamed with community scientists to measure temperatures and humidity across Nashville and Davidson County during a one-day heat mapping campaign. Once processed, the data revealed the warmest and coolest neighborhoods in our city and is being used to help inform heat mitigation efforts by city public health and environmental officials, nonprofits, urban planners, urban foresters, and researchers.

Thank you to the 142 volunteers who expressed interest in heat mapping! We couldn’t have executed our campaign without you!

Why map heat in Nashville?

In the U.S., heat waves harm more people than all other meteorological hazards combined and tend to disproportionately affect communities of color. In Nashville, climate change is predicted to worsen extreme heat more than any other weather threat. By measuring temperatures in thousands of locations across the city, this heat mapping effort revealed the areas within the city that are warmest and why these patterns in temperatures occur. Further, knowledge of heat distribution is helping to inform heat mitigation efforts to avoid adverse impacts to natural and built environments and human health, while addressing inequitable distribution of urban heat risk and vulnerability.

How are heat islands created?

Cities have a lot of buildings, concrete, and anthropogenic heat being produced, which can help trap heat near the city’s surface. This creates the Urban Heat Island effect, where cities tend to be hotter than surrounding rural areas that have more green space and trees. The effect is intensified as cities grow and in areas with little vegetation.

Even within the city, there may be discrepancies between areas with more densely packed buildings, more concrete, and varying access to heat-mitigating methods, such as increased vegetation. This mapping effort is helping to identify and understand these variations throughout Nashville.

Who is involved in Nashville’s heat island mapping project?

This project was a collaboration between middle Tennessee resident volunteers and a number of Nashville area stakeholders! Project partners included the Mayor’s Office, Metro Public Health Department, the Tennessee Climate Office, the Tennessee Department of Health, Vanderbilt University, Middle Tennessee State University, Fisk University, Tennessee State University, Cumberland River Compact, Urban Green Lab, and Adventure Science Center.

What did volunteers do?

Volunteers drove along predetermined routes in Nashville over three separate one-hour periods (6-7 a.m., 3-4 p.m., and 7-8 p.m.) on a hot and dry day, August 14. Data was collected using a specially designed sensor that attached to volunteers’ cars and collected the temperature and humidity throughout the route driven. This campaign also used volunteers who served as navigators who help direct drivers’ turns along their route.

The resulting temperature and humidity data collected is being used to develop temperature and heat index maps of Nashville which will help address heat-related vulnerabilities across the region.

When did the heat mapping occur?

Nashville’s heat mapping event occurred on Sunday, August 14, 2022 due to optimal weather for heat mapping. Ideal conditions for heat mapping are hot and clear days.

What routes were included in mapping?

Nashville’s campaign included 10 routes across the city. Images of those routes and the full study area are provided below.