The hay fever season is set to begin earlier than usual in Japan this year due to a warmer-than-average winter, a weather information provider said Wednesday.

According to Weathernews Inc., Japanese cedar trees, which along with Japanese cypress trees are one of the most prominent culprits for triggering hay fever allergies, are forecast to release pollen from a few days to a week earlier than usual across the country.

As a result, the hay fever season could begin in early February in the southern Kanto region, which includes Tokyo, and in northern Kyushu, it said.

The northern part of the Tohoku region is forecast to experience pollen releases as soon as late February, nearly half a month earlier than average, the company said.

The peak of hay fever season is forecast for around mid-February in eastern and western Japan. The southern and northern areas of Tohoku are predicted to experience peak pollen in late February and mid-March, respectively.

The weather information provider expects the pollen count from both cedar and cypress trees to reach about 85 percent of the annual average this year, although it may be higher in certain regions.