Japan recorded its first "extremely hot days" this week after three locations reached temperatures of 40°C or higher [1].
The event marks a critical milestone in Japan's climate tracking, as the Japan Meteorological Agency (JMA) introduced the specific "酷暑日" (extremely hot day) label this summer to categorize these dangerous temperature peaks [3].
According to the JMA, the highest temperature was recorded in Tajimi City, Gifu Prefecture, which reached 40.3°C [1]. Toyota City in Aichi Prefecture followed with 40.1°C, and the Yawata district of Gujō City in Gifu Prefecture hit 40.0°C [1]. These readings occurred during the afternoon of July 21 [2].
Beyond these extreme peaks, the heatwave affected the country on a massive scale. Between 270 and 272 locations nationwide recorded "猛暑日" (extremely hot days), defined as temperatures of 35°C or higher [1], [4]. This represents the highest number of such locations recorded so far this year [4].
The extreme weather cleared public spaces and disrupted normal activities. A reporter said that parks, which are usually crowded with children during summer vacation, were empty [5]. "I'm just exhausted, really. The sweat won't stop," said a festival participant [7].
Earlier in the day, conditions were already severe. A reporter said that sweat flowed even while standing still, noting that the temperature had already reached 36.1°C by 11 a.m. [6].
The JMA's introduction of the new terminology reflects a need to differentiate between standard heatwaves and the more severe risks associated with the 40°C threshold. The agency uses these classifications to alert the public to the increased risk of heatstroke, and other weather-related health emergencies.
“Japan recorded its first 'extremely hot days' this week after three locations reached temperatures of 40°C or higher.”
The creation of a new meteorological category for days exceeding 40°C suggests that the Japan Meteorological Agency views these extreme temperatures as a distinct and growing threat rather than statistical anomalies. By formalizing the 'extremely hot day' label, the government can better standardize emergency responses and public health warnings as the frequency of such heat events increases.
