Abstract
From the observational data covering from 1930 to 1931, annual and daily variations of frequencies of fogs on the Hakone-range were investigated. The maximum was found to appear in July and the minimum in December. During a day, the maximum appeared in the morning and at night, the minimum in the daytime. This daily change was especially remarkable and regular in warm seasons.
The relation between wind velocity and the rate of fog-formation was investigated and it was found that in warm seasons there was no regular relation but in cold seasons the fog appeared more frequently as the mean wind velocity increased.
As for the wind directions, it was found that, in the morning and evening, fog appeared more frequently when the wind was from SW-WSW, while in the daytime fog was more frequent when the wind was from NE-ENE. It was also found that in warm seasons, more fogs were observed when the wind was from SW-WSW, while in cold seasons when the wind from NE-ENE.
Lastly the temperature variation in fogs was investigated. When fogs with no rain lasted from morning till evening, the temperature changes was in averag 1°, 9C, for fogs with intermittent rain, the averge temperature changes was 2°, 3C, while when both fogs and rains continued from morning till evening the temperature changes was 3°, 0C in average.
