We present a comprehensive and reliable statistics of 200 mbar wind speeds at the Canary Islands based on long term climate diagnostics archive data and balloon measurements. The results demonstrate the remarkable stability of the Canarian sky, with low mean values of V200 = 22.12 ms-1 at the Roque de los Muchachos Observatory (ORM, La Palma, Spain) and provide independent confirmation of the potential of Canary Islands for adaptive optics. A comparison of V200 values from a climatological database and in situ measurements with radiosondes launched from Santa Cruz de Tenerife (Tenerife Island, Spain) reveals an excellent level of agreement, which lends confidence to the claim that climate diagnostics measurements provide a useful tool for astronomical site assessment, although a rigorous control of data quality, analysis and cross comparison needs to be performed before the method becomes extensively used. Moreover, the correlation of results for La Palma and Tenerife confirms the homogeneity of the Canarian sky at the tropopause level. The analysis of frequencies and variability of V200 led us to propose a seasonal perodicity of V200. We also compare the results obtained at La Palma with those from Mauna Kea, Paranal, and La Silla.