The depth of snow on the ground does not always coincide with the quantity of snowfall, although the two may be regarded as almost equal. I therefore do not think it irrational to regard the former as indicative of the latter. Snow-depth is greatly affected by the condition of the weather from day to day or by the yearly climate. However, after the snow attains a certain depth, we may notice its outstanding characteristics as the result of conditions peculiar to that region.
In such a district as in Yamagata, for example, except near the Oou mountain range, where it snows under the influence of northerly or northwesterly winds from the Japan Sea, the snow-depth changes with certain regularity. From observations made during the time of deepest snow, namely, from the middle of February to the beginning of March, we find certain features characteristic of this district. The writer has constructed maps showing the geographical distribution of snows, the highest records of snow-depth, and the thawing season of snows from data obtained by the primary schools of this prefecture for the last 3 years, and he finds some close relationships between them.
Generaly speaking, deep snow delays the blooming of such trees as the cherry and affects considerably early spring agriculture. To establish climatic boundaries in such snowy districts as this prefecture, it is necessary to take into consideration data covering snowfall, etc.. According to the isothawing line of snow and the isoblocmning line of cherry blossoming the writer has divided this prefecture into the following regions.
I Region of little snow
a. The Syônai field b. The southern parts of the Yamagata-basin
II Region of medium amount of snow
a. The western parts of the Yamagata-basin b. The southern parts of the Nagai-basin c. Yonezawa-basin
III Region of much snow
a. Sindyô-basin b. Gbanazawa-basin c. The Dewa hills d.The Oou Mountains.

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