Sweltering heat hit Japan on Sunday. The temperature shot up to over 38 degrees Celsius in the northernmost prefecture of Hokkaido. That's a national record high for May.
The Meteorological Agency says the temperatures soared due to hot air and strong sunshine.
In the city of Obihiro, Hokkaido, the mercury reached 38.7 degrees Celsius, an all-time high for the prefecture.
Daytime highs are expected to reach 35 degrees across the country.
The mercury already hit 31.9 degrees before noon in central Tokyo.
Authorities are advising people to take measures to prevent heatstroke.