Temperature Analysis for Common Waterwise Landscape Types in Urban Heat Island for a Denver Park
Urban heat islands intensify thermal stress in cities by elevating surface and air temperatures relative to surrounding areas. In semi-arid cities such as Denver, landscape design is an important tool in moderating these effects because the thermal behavior of urban surfaces strongly influences both daytime heating and increasing levels of stored heat. As municipalities increasingly promote waterwise landscaping to reduce irrigation demand, there is a growing need to understand how common low-water landscape alternatives compare thermally with conventional surfaces. This study evaluates the temperature behavior of representative landscape types in an urban park setting to assess their relative contributions to surface heating and potential heat island mitigation.Ìý
The temperature data was collected during the summer of 2025 at Denison Park in Denver, Colorado. The six land-cover types were turf grass in full sun, turf grass in full shade, pavement, wood mulch, native grass, and rock mulch/squeegee, with all non-shaded surfaces located in full sun. Measurements were obtained using two complementary technologies. A Kestrel instrument was used to measure atmospheric conditions, including air temperature and wet bulb temperature, while an infrared device was used to measure surface temperature. A time-series analysis of air and surface temperatures revealed clear differences in thermal behavior among the six landcover types. Pavement consistently reached higher temperatures and remained warm for longer periods than vegetated surfaces, demonstrating its strong role in amplifying local heat exposure and prolonging thermal stress after peak heating hours. In contrast, grassed surfaces generally exhibited surface temperature patterns that more closely tracked air temperature, suggesting lower heat storage and faster cooling relative to hardscape materials. This tendency indicates that vegetated surfaces may reduce the persistence of elevated surface temperatures and therefore lessen the localized thermal burden associated with urban heat islands.