Scorching heat prevailed again on Monday over wider Japan, with temperatures soaring above 39 degrees Celsius in Obama City on the Sea of Japan coast.

The Meteorological Agency says clear skies and burning sunshine engulfed western and eastern Japan, among other regions. The foehn phenomenon, in which winds blowing down from mountains become dry and push up temperatures, also reinforced the heat along the Sea of Japan and inland areas.

Daytime temperatures reached a record 39.1 degrees in Obama, Fukui Prefecture, and 38.9 degrees in Yonago City, Tottori Prefecture. The mercury topped 38 degrees in areas in Saitama Prefecture.

Temperatures are expected to remain above 25 degrees overnight, prompting weather officials to warn of heatstroke.

Temperatures are also forecast to rise further on Tuesday as a high pressure system is expected to gain strength.

Weather officials advise people to refrain from going outside and to avoid exercising during the daytime if possible.

They also urge people to use air conditioners appropriately, stay hydrated by drinking water at night, and to remove masks when they are outdoors and not engaging in conversation.

Atmospheric conditions remain unstable mainly in the region of Kanto Koshin and northern Japan.

The regions of Hokkaido and northern Tohoku may have heavy rain of 30 millimeters an hour or more through Tuesday. Stormy weather may hit some areas in Kanto Koshin, accompanied by heavy rains overnight of 50 millimeters or more in an hour.

In Kanto Koshin, there are chances of a sudden change in weather during the day. Weather officials are urging residents there to be on alert for mudslides, floods in low-lying areas and swollen rivers.