JWA 2025 Spring Pollen Dispersion Forecast (Part 1)
~Spring pollen season to start soon More than twice the usual amount of pollen is dispersed in some areas in Shikoku and Kinki~
Press Release
On January 16, 2025, Japan Weather Association (JWA) released its report on the 2025 spring pollen dispersion forecasts at both national and prefectural levels. The forecasts cover cedar and cypress pollen nation-wide excluding Hokkaido. However, white birch pollen forecast is available for Hokkaido.
1.Start of Cedar Pollen Dispersion in 2025
Cedar pollen dispersion is expected to begin in early February in parts of Kyushu and Kanto. By mid-February, a broad area from Kanto to the west is anticipated to enter the cedar pollen season followed by Hokuriku and southern Tohoku in late February. In northern Tohoku, pollen dispersion is expected to start between early to mid-March. The cedar pollen season is expected to commence at the usual time, but in Tokai and Tohoku, it is likely to begin at the usual time or earlier than usual.
According to observational data from cooperating agencies, some areas in Tokai have already confirmed the start of pollen dispersion in early January. Although the amount of pollen in January remains low, full-scale dispersion is expected to begin in February.
2.Peak Period of Cedar and Cypress Pollen
The peak period of cedar pollen dispersion, when pollen levels are significantly high, is expected to begin in late February in Fukuoka, Takamatsu, and Tokyo, while in early to mid-March, the peak is likely to occur across a wider region including Hiroshima, Osaka, Nagoya, Kanazawa, and Sendai. In various areas, the peak period is generally expected to align with the usual timeframe, and is likely to last between 10 days and one month. Additionally, the peak period for cypress pollen is generally expected between late March and early April. Due to higher-than-usual temperatures in March, the peak period for cypress pollen is anticipated to be earlier than usual, lasting about 5 days to 2 weeks. In Sendai, the cypress pollen concentration is expected to be low, with no clearly defined peak.
On days with strong winds or sudden warmer temperatures, pollen dispersion increases significantly, with some days expected to see pollen levels exceed 100 particles per square centimeter. It is advisable to regularly check pollen and weather updates, and take appropriate pollen countermeasures.
3. Pollen Dispersion Forecast for Spring 2025
Pollen levels are expected to be higher than the 10-year average in most regions from Kyushu to Hokkaido, with some areas in Shikoku and Kinki experiencing significantly higher concentrations. In northern Tohoku, however, pollen levels are expected to be lower than usual.
Pollen Dispersal Forecast:
For more information on pollen dispersal forecast, follow the link below;
https://www.jwa.or.jp/english/service/seasonal-news-pollen-dispersal-forecast/
PLEASE REFRAIN FROM USING THIS INFORMATION FOR CORPORATE PURPOSES WITHOUT PREMISSION
(QUOTATIONS IN PRESS RELEASES OR USE FOR PROMOTIONAL PURPOSES AMONG OTHERS ARE PROHIBITIED).
For corporate use, including product PR, please contact us using the inquiry form provided in the link below.
https://www.jwa.or.jp/english/contact/
Originally released in Japanese: 2025/1/16
PDF DOWNLOAD：JWA 2025 Spring Pollen Dispersion Forecast (Part 1)
