HeatWatch is a national effort to record the heat index throughout participating cities on a single day, to see how the heat index varies from one area of a city to the next. When one part of a city is much hotter than the surrounding areas, it is referred to as an Urban Heat Island. The data collected during the HeatWatch event on July 31, 2021, has been used to produce detailed maps of the cities’ urban heat islands. Using heat sensors mounted on their own cars or bikes, community volunteers traversed their neighborhoods morning, afternoon, and evening on one of the hottest days of the year. The sensors recorded temperature, humidity, time, and the volunteers’ location every second.
In 2020, the city of Charleston released an All Hazards Vulnerability and Risk Assessment report, which identified populations and assets throughout the city that are vulnerable to various physical threats. Among the threats identified in the report was extreme heat.
While the report identifies extreme heat as a pressing public health risk--particularly for low-income and elderly communities living in developed areas with low tree canopy cover--more data is needed in order to understand urban heat and its impacts and the concerns of compound risks associated with extreme heat, humidity and flooding.
How will HeatWatch help?
The HeatWatch event will provide the city better data on urban heat islands and areas of concern, helping to focus efforts to reduce the risk of heat illness in the community to the areas that need it most. This data can then be integrated into city planning decisions and used to engage citizens on extreme heat risks and mitigation strategies in urban areas. By raising awareness of extreme heat risks and by layering data into the city’s GIS system, comprehensive, equitable and multi-benefit solutions will be possible.
What can you do?
One of the many benefits of a mature tree canopy is the mitigation effect it has on heat and flooding. The following web apps explore Charleston tree canopy and helps to identify areas where new trees would be beneficial.