Average temperatures in May hit record highs in more than one-third of all observation points across Japan, the Meteorological Agency said.
Of 154 observation points nationwide, 55 logged record temperatures, with the average temperature in Sendai at 18.0 degrees, 1.5 degrees higher than the previous high of 16.5 in May 2014, the agency said Monday.
The city of Fukushima saw its average temperature for May reach 19.8, compared with 18.3 in May 1998.
The average temperature in eastern Japan, excluding the northeastern part of the country, was 2.1 degrees higher than in the average May, while that in northeastern Japan was 2.0 degrees warmer than usual. Both were the highest since officials began compiling comparable data in 1946.
With high-pressure systems covering Honshu for several days last month, the duration of sunshine was 30 or 40 percent longer on the Pacific side of northeastern Japan and the Sea of Japan side of eastern Japan than average, the agency said.
Rainfall on the Pacific side of eastern Japan was also low, logging roughly half that of the average.