Annual average wind speed off the coast of Fukushima, Ibaraki, and Chiba Prefectures. The average maritime wind speed at one location off the coast of Iwaki, Fukushima, measured over a two-year span was 7.4 meters per second, with monthly maximum wind speeds exceeding 9 m/s, compared to an average wind speed on land of just 4.3 m/s. (Courtesy Ishihara Takeshi, University of Tokyo.)