The Environment Ministry on Friday published real-time airborne pollen counts across Japan for the first time this year, via an online map.
The service will be available through the end of May at kafun.taiki.go.jp.
"I want people to use it to avoid developing hay fever and take preventive measures," a ministry official said.
The map, updated hourly, displays data from 120 locations across the country, collected by instruments that measure the amount of pollen per cubic meter, according to the ministry. The map also shows wind speed and direction.
At 3 p.m. Friday, Shinjuku Ward in Tokyo had a pollen grain count of 16, while in Nishinomiya, Hyogo Prefecture, the count was zero per cubic meter.
Data for the Kanto, Chubu, Kansai, Chugoku, Shikoku and Kyushu regions was first released Friday, while data for the Tohoku region will be added on Feb. 15 followed by Hokkaido in mid-March.
The observation system, which has been named "Hanako-san," began operating in 2002 in the Kanto region, expanding nationwide in 2007. Each year the data is released to the public, with officials hoping the data can help people avoid areas with high pollen counts.