Japan experienced a record number of extremely hot days this summer as a persistent warm air mass covered the country [1], [2].
This prolonged heatwave poses significant public health risks and disrupts daily life, forcing residents to seek unconventional cooling methods to avoid heat-related illness.
The Japan Meteorological Agency (JMA) reported that 43 locations observed "mousho-bi," or extremely hot days, which is the highest number for this time of year [1]. Additionally, 491 locations reported "manatsu-bi," which are categorized as very hot days [1]. Other reports from the JMA indicated that the number of locations with temperatures reaching or exceeding 35 °C surpassed 200 earlier this month [3].
Temperature spikes were recorded across various regions. In Hita City, Ōita, the maximum temperature reached 35 °C [1]. Kiryū City in Gunma recorded a high of 34.2 °C [1]. Further north, temperatures in Hokkaido exceeded 30 °C on July 1 [2], while Fukushima reported a peak of 38 °C [4].
To escape the intense heat, many people have turned to water activities or traveled to high-altitude destinations. Lavender fields have become popular retreats because they are approximately five °C cooler than nearby urban areas [1].
"The number of AMeDAS midsummer day locations is the highest this year," the JMA said [2].
"The number of extremely hot day locations with a maximum temperature of 35 °C or more exceeded 200 for the first time this year," the JMA said [3].
“Japan experienced a record number of extremely hot days this summer”
The record-breaking temperatures in July 2026 underscore a growing trend of extreme summer weather in Japan. The disparity between urban heat islands and high-altitude refuges highlights the increasing necessity for climate-adaptive tourism and public health strategies to mitigate the impact of persistent warm air masses.
