A broad swath of Japan was forecast to see unseasonably warm temperatures over parts of the next week, with the mercury hitting 18 degrees Celsius in Tokyo on Wednesday.

Japan Weather Association said that temperatures in the Tokyo metropolitan area could top 20 C on Thursday for the first time this year, predicting that the first strong southern winds, which signal the approach of spring, are likely to sweep over the Kanto region. It said temperatures are likely to drop slightly toward the end of the week, but rise again from Sunday through next Wednesday.

Temperatures in the Kyushu region ranged from 18 C to 24 C on Wednesday, offering a taste of early summer, according to the Meteorological Agency, while the Chugoku and Shikoku regions also experienced unseasonably warm weather, with temperatures in the 18 C to 20 C range. Okinawa Prefecture, known for its subtropical climate, saw temperatures in some areas soar to 26 C.