The fifth pollen scatter tendency
2023/04/11 12:00 Weather news
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・Pollen dispersal in western Japan and eastern Japan will exceed peak next week
・This year, the start of scattering was earlier than last year, and the onset of hay fever was also earlier.
・The amount of dispersal this year is 2.6 times that of last year, and many people feel that the symptoms are “painful” compared to last year.
[Currently]Cypress pollen is scattered from Chugoku-Shikoku to Kanto, and cedar pollen is scattered in Tohoku
On the other hand, in Hokuriku and Tohoku, where the amount of cypress pollen is originally low, the amount of pollen is decreasing, and in Kyushu, both cedar pollen and cypress pollen have already peaked. In addition, Hokkaido’s white birch pollen has not yet started to disperse.
[Future forecast]Pollen dispersal in western Japan and eastern Japan will exceed peak next week
In Hokkaido, where the birch pollen season is about to begin, birch pollen is expected to start flying from mid-April onwards due to the effects of high temperatures. The peak of scattering is from late April to early May in southern and central Hokkaido, and from early to mid-May in northern and eastern Hokkaido. It is expected that the amount of dispersal will decrease in late May.
[Features of this season]
The dispersal started earlier than last year, and the onset was earlier
The timing of the start of dispersal was roughly the same as in a normal year, but compared to last year when the strong cold weather persisted, many areas were about 10 days earlier. At the end of February, western Japan and eastern Japan entered the full-scale scattering season, and pollen began to disperse in the southern Tohoku region.
From the end of February onwards, unseasonably warm weather continued, and in northern Tohoku, both the start of dispersal and full-scale dispersal were about a week to 10 days earlier than normal.
Compared to 2022, the number of people who answered “as usual” and “late” decreased, and the number of “early” increased significantly. This year, the dispersal started earlier than last year, so it is thought that the number of people with early onset has increased.
The amount of scattering by the end of March is about 2.6 times that of 2022
From now on, the amount of pollen scattered will gradually decrease, but there is still a possibility that a large amount of pollen will be scattered temporarily, so it is necessary to continue to pay attention to the large amount of pollen scattered.
The amount of pollen dispersal is mainly affected by the sunshine hours and temperature of the last summer of the previous year, and the trend of increase and decrease in the amount of dispersal each year. In the summer of 2022, although the sunshine hours were slightly below normal, mainly in northern Japan, the average temperature was significantly above normal throughout the country, which is thought to have encouraged the growth of male flowers. In addition, the fact that there were many sunny days and high temperatures from the end of February to March, when the dispersal peaked, is thought to have contributed to the increase in the dispersal amount.
Many people feel that the symptoms of hay fever are “hard” compared to last year
As a result of the aggregation, there were more people with more painful symptoms than last year in all areas. In particular, in western Japan and southern Tohoku, the percentage of those who had a hard time increased by nearly 10 points, indicating that it was a harsh spring for those with hay fever. In addition to the large amount of dispersal, the start and peak of dispersal were earlier than last year, and it is thought that many people felt that countermeasures were not in time and that it was difficult.
