The number of train accidents caused by strong winds has followed a downward trend since the commercial opening of Japanese railways in 1872. Specifically, the number of accidents per train kilometer decreased remarkably to 1/100^th of its original level over a period of 100 years. This reduction is considered to result from the regulation of train operation. The probability of trains encountering winds of a critical speed can be reduced through train operation suspension for a certain number of minutes in particular sections. This paper introduces a method to calculate the probability of trains encountering winds of a critical speed in cases where they follow operating regulations strictly.