New tools have been developed to help cities identify where planting urban trees could most effectively reduce heat. Many cities aiming to cool hot streets often set general goals for increasing tree cover, but these goals sometimes miss the fact that not all shade is equally helpful, and not every neighborhood has space for more trees. Two new studies by researchers at the University of British Columbia (UBC) offer a more precise way to identify where trees can have the biggest impact. Tested in Kelowna, British Columbia, the tools can pinpoint urban heat hotspots down to individual blocks and determine where new trees could provide the most relief. "Cities often know they need more tree cover, but they still need to decide exactly where planting is possible and where shade will make the most difference," said Dr. Melissa McHale, a professor at UBC and senior author of both studies. "These approaches help move from broad citywide targets to decisions at the scale of streets and neighborhoods where people actually experience heat." Satellite thermal maps give cities a wide view of surface temperatures, but they often lack the detail needed for precise planning. Standard satellite images use 30-meter pixels, which can blend together the temperatures of rooftops, asphalt, lawns, and tree cover into a single average. In the first study, published in the journal Remote Sensing, UBC researchers tested a machine-learning method that sharpens satellite imagery from Landsat and Sentinel-2 satellites to a 10-meter resolution. This higher-resolution mapping revealed nearly five times as much temperature variation across Kelowna. Using the conventional 30-meter imagery, hot spots appeared in broad areas averaging 18,000 square meters (4.4 acres), about the size of two and a half Canadian football fields. The 10-meter approach, however, detected much smaller hot spots, as small as 700 square meters (7,500 square feet), roughly the size of a large residential lot. Landscape features like tree cover and paved surfaces explained more than 65% of the additional temperature detail, showing that the method was detecting real differences in the environment, not just digital noise. Although surface temperature is not the same as air temperature, the technique is freely available and could help cities identify smaller hot spots that traditional mapping might miss. Identifying heat-prone areas is only part of the challenge; cities also need to know where trees can realistically be planted and where they will be most useful. In the second study, published in Urban Forestry & Urban Greening, the team used a modeling tool called CanopyFit, developed by McHale and her team, to map where new trees could be planted. The model excludes areas that are unsuitable for planting, such as buildings, sports fields, underground utilities, wildfire buffer zones, and environmentally sensitive areas. It then evaluates the potential for shade alongside heat exposure and social and economic needs. Across Kelowna, the model identified space for 248 hectares (610 acres) of new mature tree cover, but the opportunity was highly uneven. Just 20% of the analyzed area accounted for more than half (50.8%) of all potential shade gains. The analysis also highlights different solutions for different neighborhoods. Some areas are "win-win" zones where high heat and social needs coincide with ample planting space, offering particularly large benefits from new trees. Other areas face high heat and greater need but have little room for new trees, suggesting alternatives like removing asphalt, adjusting development rules, or installing engineered shade structures. Both methods use adaptable frameworks and widely available data, which means other cities can combine them with local information to develop their own heat-reduction strategies. "Cities have limited space and resources for planting, so we need to be strategic," said McHale. "The goal is to establish and sustain large, healthy trees where their cooling and other benefits are needed most. Where the built environment leaves little room for trees, the findings can help cities identify barriers to planting and assess other approaches to providing shade."