Hita City in Oita Prefecture recorded a temperature above 35 degrees Celsius on Monday, marking Japan's first extremely hot day of 2026 [1], [2].
This early spike in temperature increases the immediate risk of heatstroke across the country during a period when many residents are not yet prepared for summer conditions. The sudden arrival of extreme heat in May suggests a volatile start to the seasonal transition.
The temperature reached 35 degrees Celsius [1] shortly before 1 p.m. [2]. This event marks the first time in 2026 that any location in Japan has hit the threshold for an extremely hot day [3]. According to historical data, this is only the fifth time since statistics began that temperatures have reached 35 degrees Celsius or higher during mid-May [3].
Officials said that this year's milestone occurred three days earlier than the corresponding measurement from the previous year [3]. The heat was driven by a combination of strong sunlight and the influence of warm air masses [4].
The Japan Meteorological Agency warned that the probability of high temperatures continuing from May through July is 70 percent [5]. The agency said, "There is a high possibility that temperatures will be high from May to July this year" [5].
Local authorities are urging the public to take precautions against heatstroke, as the unseasonable warmth creates a dangerous environment for those outdoors. The agency continues to monitor the movement of warm air across the Kyushu region to determine if other areas will experience similar spikes [1], [4].
“Hita City recorded a temperature above 35 degrees Celsius on Monday, marking Japan's first extremely hot day of 2026.”
The occurrence of an extremely hot day in mid-May, occurring three days earlier than last year, indicates a potential shift in seasonal norms for Japan. With a 70 percent probability of sustained high temperatures through July, the public health infrastructure may face an extended period of heat-related stress, requiring earlier deployment of cooling centers and heatstroke prevention campaigns than in previous years.
