On August 28, we sent nearly 40 volunteers armed with handheld sensors, smartphones, and smartwatches to help collect urban heat data around town. This citizen science campaign was in partnership with the NC Museum of Life and Science and the Town of Chapel Hill, and is part of our effort to better understand the urban heat island (UHI) effect in Chapel Hill.

The UHI effect is a phenomenon where cities or urban areas experience much hotter temperatures than nearby rural areas. This is because impervious surfaces, like roads and buildings, absorb and re-emit more heat than natural surfaces, like grass and trees. Having a lot of people and cars concentrated in an area can generate heat, too. And as climate change increases the likelihood of heatwaves, the UHI effect is being worsened.

Volunteers at one of our five hubs in Chapel Hill. Extreme heat hurts animals, too!

To collect data in Chapel Hill, each of our volunteers walked (and one biked) 2-3 mile routes in one of five different hotspots: Chapel Hill North, Franklin Street, University Place Mall, Glenwood Square/Meadowmont, or Southern Village. These hotspots were identified using the Town of Chapel Hill’s Extreme Heat Resiliency Assessment map.

Then our analysts designed one or two routes for each of these hotspots, where volunteers carried handheld PocketLab sensors to record temperature data. They also collected heat comfort data with the app Cozie, using it to track if they were hot, warm, or comfortable at different times along their route.

Top: Downtown mapping route. Bottom: University Place mapping route. 

By the end of the day, our volunteers had collected 46 temperature data files and nearly 200 heat comfort data points. And now, we can use this data to better understand urban heat and heat stress in some of the most vulnerable-to-heat hotspots in Chapel Hill.

Left: Hub locations. Right: Cozie thermal comfort data collection from the campaign.

We’re still in the process of analyzing the data we collected, and there’s a lot we can do with it. Not only can we build an urban heat island model or a map of heat comfort zones in Chapel Hill, but we can also identify vulnerable areas and neighborhoods by incorporating data like household income or other demographics into our analysis. A 2021 study co-authored by DDL researchers found that the average person of color is more likely to live in an area with intense UHI impact. 

To all the volunteers that made this campaign possible and the nearly 90 people that have expressed interest in this campaign – thank you! If you participated, take this quick survey to tell us about your experience: https://forms.gle/P7r9bPa9AJmCK1v66