Rising temperatures were set to hit a broad swath of the Kanto region on Monday and Tuesday, though the mercury is forecast to plunge later this week, sparking concerns about the health impacts associated with abrupt temperature shifts.

According to the Meteorological Agency, warm air circulating from the south around the perimeter of a high-pressure system is expected to drive temperatures upward nationwide. On Monday, temperatures rose to over 16 degrees Celsius in Tokyo, 19 C in cities such as Fukuoka and Niigata, and 21 C in Kanazawa, comparable to levels typically experienced in early April to mid-May.

The unseasonably warm conditions are particularly evident in Hokkaido, where temperatures have reached a record high for February in Sapporo on Monday. In northern Japan, which is more accustomed to snow, there have been warnings issued against avalanches and melting snow that could cause landslides and flooding in low grounds.

However, this warm spell is expected to be fleeting, with temperatures forecast to plummet by over 10 degrees in Tokyo by Wednesday, raising concerns as the sudden temperature drop may impact the health of some individuals.

Furthermore, according to private forecaster Japan Weather Association, a front is forecast to stall this week around Japan’s main island of Honshu, with low pressure developing intermittently over the front. This pattern may cause fluctuations in atmospheric pressure, which may cause some discomfort such as headaches and joint pains, particularly for residents of Tokyo and the surrounding Kanto region.

Simultaneously, rainfall is predicted to gradually spread across western, eastern, and northern Japan on Monday. The Meteorological Agency has cautioned against sudden heavy rainfall, gusty winds, lightning strikes, and tornadoes, urging vigilance amid these weather developments.