Summer in Japan will be hotter than usual, according to the Meteorological Agency’s three-month forecast.

The average temperature nationwide from June to August is expected to be higher than normal, with a 50% probability of above-normal temperatures forecast for northern and eastern Japan, the weather agency said in its latest forecast published last week.

In June, when many regions are expected to enter the rainy season, the agency forecast that there will be more rainy days than in an average year.

According to the Japan Weather Association (JWA), the Koshin region in central Japan and the Kanto region around Tokyo are expected to enter the rainy season around June 12, later than in an average year. In the region centered on Osaka Prefecture, the rainy season is expected to start on June 11.

The JWA had been forecasting that the rainy season would come earlier than in an average year, but a buildup of high pressure is expected to keep the seasonal rain front from moving northward, delaying its start.

On Sunday, Japan experienced the hottest day of the year so far, with the mercury in some cities reaching 35 degrees Celsius or higher — the first time in three years that temperatures that high were reached in May.

The cities of Takasaki in Gunma Prefecture and Sano in Tochigi Prefecture recorded temperatures of 35.2 C. Other hot spots included Koga in Ibaraki Prefecture and Toyota in Aichi Prefecture, which saw the mercury rise to 34.5 C and 34.4 C, respectively. Kumagaya, Saitama Prefecture, which is known for its heat, recorded a temperature of 33.8 C on Sunday.

Temperatures rose in the Kanto and the central Tokai region due to warm winds blowing around the edge of a high-pressure system, according to the Meteorological Agency, with the temperature reaching 31.2 C in central Tokyo.

Around 260 locations that the agency monitors nationwide, or roughly 30%, saw temperatures rise above 30 C.

“I’m not going to hesitate using the air conditioner to get through the summer,” said Tomomi Yauchi, a 43-year-old Kumagaya resident who on Sunday was visiting a shopping mall with her family.

Last year, the nation’s first day with temperatures of 35 C or above was observed on June 9 in three cities. The last time such a hot day was reported in May was in 2019, in Taketa, Oita Prefecture, when 35.0 C was recorded on May 25, according to the JWA.

Information from Kyodo added