Japan experienced another day of extremely high temperatures on Sunday, with the mercury topping 35 degrees Celsius in many parts of the country in the morning.

The Meteorological Agency said a high pressure system covering the archipelago pushed up temperatures from early morning.

By 11 a.m., Otsuki City in Yamanashi Prefecture recorded 37.2 degrees, and Kamaishi City in Iwate Prefecture registered 37 degrees.

Weather officials say daytime highs were likely to reach at least 39 degrees across the country, and urged people to take precautions against heatstroke.

Japanese officials have issued heatstroke alerts for most parts of the country. They warn that the risk of developing heatstroke is extremely high.

The intense heat is expected to continue through Friday.

Environment Ministry officials say heat-related deaths tend to surge when intense heat continues. The number of people suffering from heatstroke is rising. Some individuals have died.

The officials are calling on people to remain vigilant, use air-conditioners and stay hydrated. They are also urging people to avoid going outdoors unless it is absolutely necessary.