Number of days in a year with strong winds

Reference: Hydrometeorology and Hydrochemistry of Seas (1992). Volume VI The Caspian Sea. Issue 1 Hydrometeorological regime. Eds. F.S. Terziev, A.N. Kosarev, A.A. Kerimov.

Number of days in a year with strong winds (V >= 15 m/s), m/s
Number of days in a year with strong winds