Formulas of different types for use in minimum temperature forecasting have been proposed by many authors. It is well known that the morning minimum temperature is function of several variables, but the effect of some of them is obscure, so there are difficulties in the way of applying formulas in actual practice.
In this paper, the present author further studied the hygrometric formula which was proposed by Ellison and others, and using the data observed on frosty night at Gihu, obtained the equation of the first degree as an empirical formula.
Applying the formula above obtained in actual practice, keeping in mind the result of the investigation on the moisture of the earth surface, the state and the path of high, which causes a frost damage, he drew out a satisfactory result.
Also he classified the investigations in our country according Ellison's classification and discussed its applicability to the Gihu district.
And also, following Ängstrom's treatment, here a conclusion is drawn that the law of Kammerman comes to naught at Gihu.