Urban Air Mobility (UAM) is an emerging concept of air transportation where small package delivery drones to passenger-carrying air taxis operate over populated areas from small towns to the largest cities. This could revolutionize the way people move within and around cities by shortening commute times, bypassing ground congestion, and enabling point-to-point flights across cities. In recent years, several companies have designed and tested enabling elements of  this concept, including; prototypes of Vertical Take-Off Landing (VTOL) capable vehicles, understanding of operational concepts, and development of potential business models. While UAM may be enabled by the convergence of several factors, several challenges could prevent its mainstreaming, such as weather.