Climate change is expected to lengthen the growing season for plants in many temperate regions. The purpose of this study is to develop future growth estimates for trees in Earlscourt Park, Toronto. The i-Tree Forecast model, in combination with climate change scenarios provided by the Canadian Climate Change Scenario Network, were used to build trajectories of future tree growth and mortality. Tree growth forecasts were greatest for the climate change scenario with the longest growing season length. Results highlight future vulnerability in two tree species common to the park, honey locust and Norway maple. A comparison of the leaf area estimates produced by i-Tree Streets and i-Tree Eco was also conducted. These models showed differences in their prediction of leaf area, a key metric for ecological service provision. Forecasting tree growth and mortality in urban parks can inform management plans that seek to maximize the flow of future ecological benefits.