As the use of unmanned aerial vehicles (UAVs) expands, wind and turbulence observations near surface in urban areas are crucial for safe flight planning. In summer 2021, a field campaign was conducted in the suburbs of Seoul, South Korea, using UAV equipped with a sonic anemometer. Horizontal winds were measured at 1-Hz up to 150 m above ground level during research flights. From 1-Hz winds, the cube root of energy dissipation rate (EDR), an objective measure of turbulence intensity, was computed using inertial dissipation methods. Stronger turbulence was observed at lower altitudes near surface than at higher altitudes, likely due to dominant surface shears. Regionally, higher EDRs were found in walk roads along rivers compared to building-surrounded areas, likely due to flows blocked by buildings. Current results highlight need for strategic UAV flight planning considering turbulence at different altitudes and urban structures, supporting safer UAV flight routing.