Development of an urban heat island relies on the ways in which the urban surface exchanges fluxes with adjacent atmospheric layers, including solar and longwave radiation to and from buildings, roads, and green spaces; along with their ventilation, exhaust, moisture, energy budgets, and small-scale advection. These processes within city neighborhoods affect both the spatial variability of atmospheric characteristics and the extremes of the overall urban climate. We investigate the impacts of the densification of the Washington, DC urban morphology from 1999 to 2015 on neighborhoods' ability to withstand a heat wave similar to that which occurred in July of 2010. We embed 10m resolution neighborhood building footprints and heights from each of the years 1999 and 2015 in the Weather Research and Forecasting (WRF) model and run simulations for each morphology using 2010 initial and boundary conditions. We then examine the resulting meteorological output to evaluate the effect of additional buildings on overall urban heating.