Weather officials in Japan say the country's sea surface temperatures in August were the highest on record.

The Meteorological Agency says the average water surface temperatures of the Pacific side of eastern and western Japan, as well as the southern islands of Okinawa and Amami, were around 30 degrees Celsius last month.

Temperatures neared 40 degrees Celsius in many parts of Japan on Monday as a heat wave continues to grip the country.

At 10 minutes past noon, the mercury rose to 41.1 degrees in the central Japanese city of Hamamatsu, Shizuoka Prefecture. The figure equals the national record set in Kumagaya City, Saitama Prefecture, in July 2018.

Temperatures soared across most of Japan on Tuesday, with the mercury topping 35 degrees Celsius in southern and western regions.

The Meteorological Agency says clear skies brought by a high pressure system extending from western to northeastern Japan, combined with an influx of warm air from the south, have caused temperatures to soar.

Temperatures soared across much of Japan on Monday.

Some cities in southwestern Japan saw the mercury exceed 35 degrees Celsius. Weather officials say the heat will linger on Tuesday.

Temperatures exceeding 30 degrees Celsius were observed in wide areas in Japan on Monday. Hot weather is also forecast on Tuesday.

Daytime highs rose to 33.4 degrees in Kofu City, west of Tokyo, and Kiryu City, north of the capital.