Weather officials say 2023 is expected to be the hottest year on record for Japan.

The Meteorological Agency analyzed observation data across the country from January through November.

It found the country's average temperature over the 11 months was 1.34 degrees Celsius higher than usual. The gap is far bigger than the full-year margin of 0.65 degrees in 2020, when the average hit a record high.

Officials say the average for all of 2023 is on course to be the highest since recordkeeping began in 1898.

In addition to global warming, they point out that Japan tended to be covered with warmer air from spring to fall as westerlies blew relatively north. They also cite stronger high-pressure systems in the south of Japan.

The average sea surface temperature near Japan is also expected to be the highest this year since comparable data became available in 1908. The figure for the 11 months through November was 1.07 degrees higher than usual, significantly larger than the record full-year gap of 0.74 degrees in 2021.

Hirai Masayuki at the Meteorological Agency says he has been surprised to see the wide margins. He says temperatures are on the rise as global warming advances, and that the number of days with extreme heat is also likely to rise. He warns that measures are needed to address the problem.

The agency says the average global temperature from January through November was 0.53 degrees higher than usual. The annual figure is also expected to reach the highest since recordkeeping began in 1891.