The official temperature outside during a hot San Antonio summer day might be 98 degrees, but how hot does it feel to residents living in urbanized areas of the city such as the near West Side?
They might feel even hotter standing on a street corner or in a room with no air conditioning, and two local researchers — one from the Southwest Research Institute and the other from UTSA — want to study those variations.
The researchers will work together to place sensors in representative locations around the near West Side to measure the “felt heat” in several typical city environments, including inside some residents’ homes. The sensors will gather data on the different components that affect how we experience heat: airflow, wind speeds, relative humidity, air temperatures and dew points.
The year-long comparative study, which begins in January, will allow scientists to record what times of the year residents in these areas are most affected and will allow the researchers to better pinpoint exactly what is causing more intensely felt heat in specific spots.
The study was the result of discussions between SwRI, UTSA, the City of San Antonio and several local equity-focused climate action groups, said Stuart Stothoff, a principal scientist with SwRI’s Chemistry and Chemical Engineering Division who is leading the study with Esteban Lopez Ochoa, an assistant professor of Urban and Regional Planning at UTSA.
The groups want to learn more about how the urban heat island effect is affecting San Antonio, he said. Heat islands are areas where temperatures are higher than outlying areas due to the presence of pavement, buildings and other surfaces that retain heat.
“We’re continually getting hotter, and so there’s been discussions for years about different kinds of studies and ways to mitigate the heat,” Stothoff said. “The City of San Antonio is very concerned [about climate change], and they’re trying to be very proactive. So what we’re hoping is that the kind of information that we’re getting here … [will] help with their planning and their resource commitments.”
His comments come as San Antonio endured its hottest and second-hottest summers on record consecutively.
Residents who live in the inner city where there tends to be more paved and impervious surfaces and less greenery are experiencing different, more intense levels of heat during these types of summers, Lopez Ochoa said. According to existing city data, many of these residents have lower incomes, meaning a disproportionate number of low-income residents in San Antonio experience more intense levels of heat, he said.
Stothoff and Lopez Ochoa said they eventually hope to expand the study into other areas of San Antonio, but they decided to start with the near West Side because it’s a commonly underserved area within the city. The two men have spent years building relationships with residents in this area by going to meetings of the Historic West Side Neighborhood Association, Lopez Ochoa said.
“I’ve been working two years with the community since I arrived at UTSA,” Lopez Ochoa told the San Antonio Report. “I go every week there to have a meeting with them to explain what we’re doing and ask their feedback.”
Part of the study will include putting sensors inside participants’ homes, to see how much heat these residents are experiencing, he said. Researchers also will be testing different areas outside such as sidewalks in the direct sun and in the shade, paved surfaces such as streets and in the open air.
Recent measurements by Lopez Ochoa showed temperatures as high as 154 degrees Fahrenheit just above a paved street.
The study is being funded in part by a $125,000 grant from the Connecting through Research Partnerships Program. It will be a year-long project. Once the data gathering is complete, SwRI will create a model to further evaluate the felt heat and to adapt publicly available weather data to better represent the temperatures on the West Side.
“We’re working to precisely characterize what’s going on in this unusually hot area of the city, so that eventually a solution can be found to alleviate it,” Stothoff said.
