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.

Even parts of Honshu that have not typically been associated with warm weather during the winter are feeling the heat.

Temperatures in the Kinki, Tokai, and Kanto Koshin regions hovered around 18 C, reaching 19 C in Kanagawa Prefecture and 20 C in Chiba Prefecture. Meanwhile, in the Hokuriku and Tohoku regions, temperatures more than 10 C above normal were recorded, with some areas nearing 20 C, as a handful of locations in Tohoku recorded their highest ever temperatures for February.

The temperature shift has been particularly noticeable in Hokkaido as warm air flows in from the south. On Wednesday, huge swaths of the prefecture reported their highest temperatures ever recorded for the month, with the mercury soaring as high as 13.1 C in Hakodate.

On Tuesday, the city of Sapporo posted temperatures above 10 C, the warmest February temperature in 55 years. The Sapporo District Meteorological Observatory has issued warnings for residents to remain vigilant against avalanches and rapidly thawing snowfall accumulations suddenly falling off roofs.

The rising temperatures have raised concerns about increased cedar pollen dispersal and heightened allergies across the country. Experts anticipate further temperature records will be broken over the next week as the warm weather persists.

Meanwhile, the Meteorological Agency is urging residents of the quake-hit Noto region in Ishikawa Prefecture to be careful, as ground affected by the New Year¡¯s Day earthquake has been loosened, and even a little rain could prompt landslides in the area.