November 28, 2021
Hatsushimo is the first frost that falls from autumn to winter of that year. Or the day when the frost fell (the first day of frost).
1981-On average for 2010, Asahikawa is October 8, Sapporo is October 25, Sendai is November 10, Tokyo is December 20, Nagoya is November 27, Kyoto is November 18, December 5th in Osaka and December 12th in Fukuoka. There is a large difference in time depending on the region, but it is highly correlated with the low minimum temperature, and when compared at the same point, the inland and highlands where the morning chill is severe is faster than the coast. 1941 --The 1970 average yearly distribution map shows September in the highlands from Central Hokkaido to Eastern Hokkaido, most of Hokkaido and North Tohoku, inland from South Tohoku to the Hida Mountains, and October in parts of the Chugoku Mountains and Kyushu Mountains. , Most of the other areas north of Kyushu are in November, and some of the south and west banks from Kyushu to the Boso Peninsula are in December.
As a guide, the minimum temperature is about 5-6 ° C in the morning when it is sunny and the wind is calm and the radiative cooling is strong. At this temperature, the ground surface temperature becomes just around 0 ° C and frost begins to fall. However, frost may not occur when it is raining or snowing, when the humidity is low and the dew point does not reach the ground surface, or when the wind is strong and the atmosphere is agitated and the temperature does not drop easily. Frost causes frost damage to crops, so the time of the first frost is a guide to start countermeasures against frost.
In many parts of Japan, the first snow often comes after the first frost, but in some cases the first snow is earlier. On average in 1981-2010, the first snowfall was slightly earlier in Niigata, Kanazawa, Kobe, and Hiroshima, 16th in Wakkanai, and 29th in Shimonoseki. Similarly, Hatsushimo is slower than Hatsushimo, but there are exceptions.
Due to the heat island phenomenon caused by urbanization and the effects of global warming, it has tended to slow down in recent years. Looking at the changes in Tokyo, until the 1930s, there were no observations in December in the center of November, and the first frost in late October was also seen, but from the latter half of the 1970s to the center of December, the year shifts to January. Begins to appear. 1988-The first frost in November was not observed at the end of November 27, 1989. The winter of 1994-1995 was February 6th, which was unusually late.
The succulent plant of the family Hylotelephium, Graptopetalum paraguayense, has been cultivated in Japan for a long time under the horticultural name of "Hatsushimo". See Graptopetalum.
The earliest first frost in Hokkaido is Sapporo on September 9, 1888 (statistics started in 1877), and the latest first frost in Muroran is December 21, 1965 (statistics started in 1924).
The earliest first frost in Sapporo was September 9, 1888, and the latest first frost was November 15, 2005 (statistics started in 1877).
The earliest first frost in Sendai was October 3, 1944, and the latest first frost was December 3, 2004 (statistics started in 1927).
The earliest first frost in Tokyo was October 21, 1909 and 1937 (statistics started in October 1876), and the latest first frost was February 6, 1995.
The earliest first frost in Nagoya was October 13, 1899, and the latest first frost was December 18, 2004 (statistics started in 1891).
The earliest first frost in Fukuoka is October 21, 1903, and the latest first frost is January 21, 2005 (statistics started in 1932).
Normal value of cold season phenomenon (1981-2010 statistical value) --Statistics such as first frost and last frost of the meteorological office in Sapporo District Meteorological Observatory (Hokkaido).
First and last frosts in Tokyo-Statistics of first and last frosts in Tokyo (Otemachi, Chiyoda-ku, Japan Meteorological Agency). Note that the observation location has changed since 1876.
Normal value for first frost, first snow, etc. by prefecture
Geospatial Information Authority of Japan Japan National Census Map Book (1977) Frost.