UPDATE: We held the WiST Heat Watch mapping campaign on Sunday July 21st. Thank you to everyone who volunteered to participate and to those who spent their Sunday with us! Check back here for updates. We will be scheduling webinars and meetings to report the results once the data is analyzed!

The UD Climate Change Hub is partnering with DNREC, the Center for Environmental Monitoring & Analysis, community organizations, and residents to measure heat across Wilmington and surrounding townships (WiST) this summer. The WiST Heat Watch campaign is one of 15 urban heat watches supported by the NOAA Urban Heat Island (UHI) program for 2023. Dense buildings, fewer trees, and more heat-absorbing concrete can make urban areas up to 20 degrees hotter than greener suburbs, an effect known as urban heat islands, and extreme heat can cause or exacerbate a range of health concerns. Across the United States, heat waves are the most deadly weather-related hazard. Understanding what areas of north-eastern Delaware face the greatest heat will help local, regional, and state officials and organizations to find ways to improve heat safety.

In July, resident volunteers will drive pre-selected routes with a window-mounted temperature sensor on their cars (see image below) in the morning, midday, and evening, giving us a snapshot of how heat changes across the day and across neighborhoods. The exact day of the campaign will be selected depending on weather conditions to find a clear, sunny, hot day. (See this news story from Delaware Online about the campaign!)

To learn more, come to our June Town Hall, sign up to receive email updates, or sign up to learn more about being a volunteer.

Two people are holding a plastic sensor - a long blue tube - in the car window while the window rolls up to hold it in place.
Installing the temperature sensor. It rolls into the window and does not damage the car or obstruct the view.


We held or first virtual town hall on Friday, June 2nd. You can see the slides and a recording of the presentation from that meeting here:


Fill out this interest form to (a) receive updates about the WiST Heat Watch or (b) to learn more about becoming a volunteer! Your information will be kept private, used only for WiST Heat Watch 2023, and deleted after the end of the project.

Know a person or group who might be interested? Share our one-page flier!


Where is the campaign happening?

Map of northern Delaware with an orange shaded area around Wilmington, extending west around Elsmere and Newport, south to New Castle, and northeast to Ardentown.
Temperature data will be collected in areas highlighted in orange. CAPA Analytics, working with the NOAA Urban Heat Island program, will identify the best driving routes to cover a wide range of land use types and sites within the study area. The exact study area may change slightly as those routes are determined.

What is being funded? 

The heat assessment project (“Heat Watch”) involves collecting high-resolution near-surface air temperature (NSAT) data for the purpose of developing a predictive temperature and heat index model (Houston example) that takes into account the effect of land cover and topography (i.e., trees and hills). Deliverables provided by the project include maps of predictive surfaces, study data (temperatures) and a final report describing the methods, results, and initial interpretations.

How does this mapping support Delaware communities? 

The information generated by this project ties into many existing programs and priorities, including: public health, energy efficiency, resilience, climate change mitigation, climate preparedness, emergency management, urban forest management, land use planning, equity and social justice, and community partnerships and engagement. Here’s a few examples of how other UHI Heat Watch campaigns have used the information:

  • Portland (OR) combined the heat mapping data with demographic information and air quality data to better characterize the risks of the urban heat island effect and poor air quality on vulnerable communities. The information is also being used to inform heat mitigation strategies such as cooling centers, drinking water distribution hubs, and tree plantings.
  • Richmond (VA) is using the mapping project to inform the next long-range city planning document (Richmond 300) and the next round of sustainability planning (RVA Green 2050). One Richmond heat-mapper noted that since the project was done in July 2017, “public chatter about the urban heat island effect and its impacts on energy, health, and infrastructure has been markedly present throughout the year.” 

How are the temperature data collected?

Data are collected in three 1-hour blocks over the course of one day chosen to represent one of the hottest days in the year. Data are collected by mounting a temperature sensor on the passenger side of a car and driving the vehicle across a pre-determined route. Those data are then used to create an area-wide predictive model based on the statistical relationships between land cover and temperature. If you are interested in serving as a driver, navigator, or volunteer, please fill out the interest form linked above, and we will send you more information about the roles.