COLORADO—Have you ever checked your weather app and thought, “Really? I could have sworn it was at least five degrees hotter…” In some cases, you could be right.

This summer, two research teams out of the USDA Forest Service Rocky Mountain Research Station Denver Urban Field Station conducted studies that may help explain why some urban areas feel hotter than others. Specifically, they looked at how landscape design, vegetation and shade can affect thermal comfort in urban Denver and Fort Collins, Colorado. The researchers’ findings can inform city planners and urban residents about how to design landscapes that help beat the heat and where the need is greatest. Using natural means like trees and landscaping to mitigate urban heat could benefit public health and well-being, create more equitable access to nature and strengthen community resilience against climate change.

Imagine standing in a parking lot surrounded by parked cars and black pavement. Then imagine standing in a yard lush with plants, trees and shade. The difference between these two microclimates has to do with how the sun’s energy interacts with our surroundings. Solar radiation reflection from the pavement causes the “real feel” temperature to be hotter. Uneven distribution of heat exposure leads to inequitable distribution of heat-related impacts to the health and well-being of urban residents. This is especially true when temperatures approach extreme highs as they did in summer 2023.

The Denver research team collected thermal heat and other microclimate data to pair with social surveys conducted by university partners at bus stops. The surveyors asked transit riders about their thermal comfort levels and perspectives on bus stop aesthetics. With the micro-meteorological measurements, this information will shed light on how extreme heat might disproportionately effect transit riders.

The research team in Fort Collins focused on how different types of vegetation and tree canopy cover effect the microclimate around homes. The researchers visited residential yards, which they categorized based on characteristics such as yard composition, location attributes and directional orientation. Accompanying the crew was an advanced lab cart called MaRTa, a biometeorological data collection machine on wheels. Results based on MaRTA’s measurements will equip agencies and residents to design safer, more comfortable, and more pleasing cityscapes and yards throughout urban areas.

Taken together, this research will enable city planners and others to take feasible actions that yield measurable improvements to urban ecosystems, health and well-being of residents, and environmental justice in urban heat islands across the region.

The Denver Urban Field Station is a collaborative research and practice unit that explores connections between people and nature and the role of vegetation in semi-arid cities, towns, and developing regions. It’s also part of a nationwide network of urban field stations, which aim to facilitate opportunities to advance knowledge co-production, long-term social-ecological research, and knowledge exchange. Partners of these studies included the U.S. Geological Survey, Colorado State Forestry, the University of British Colombia, the city of Fort Collins and the University of Colorado-Denver.