Further to the mean wind profiles discussed in Chap.  4 , this chapter details current understanding of turbulence characteristics in the atmospheric boundary layer over homogeneous terrain. Key topics include turbulence intensity, gust factor, turbulence integral length scale, wind spectrum, and coherence. The chapter begins with an overview of turbulence characteristics in neutral atmospheric stability conditions (Sect. 5.1), followed by a brief introduction to those in non-neutral conditions (Sect. 5.2). Recent observations of turbulence in severe storms, including tropical cyclones and thunderstorms, are also presented (Sect. 5.3).