Tracking Japan’s High-Temperature Days in 2026

Disaster## Temperatures Rising in 2020s

Data from the Japan Meteorological Agency shows that as of August 4, there was a cumulative total of 4,727 days in 2026 with a maximum temperature of 35° Celsius or higher at the agency’s observation stations across Japan. (This figure adds together all the locations each day that reach the temperature.) Based on comparable statistics since 2010, this is the second highest number of days at this stage of the year, trailing only the 6,144 recorded in 2025.

From 2010 to 2020, there were only four years when the total rose above 1,000 as of the end of July, but it has topped this level every year since 2022.

In 2026, the JMA introduced the term kokushobi (“severe heat day”) for days when the temperature rises to 40° Celsius or higher. This extreme heat was recorded at three JMA observation sites including Tajimi, Gifu, on July 21, and the Tōkai region in central Japan recorded temperatures of 40° or more for five consecutive days through July 25. As of August 2, the cumulative total of kokushobi was 27 for 2026. This was second only to 2025, which had recorded 30 at the same point in the year.

According to the JMA, contributory factors to temperature increases include the westerly jet stream flowing farther to the north than average near Japan, the Tibetan High pressure system extending over western Japan, warm air flowing in from the Pacific High, and the effects of global warming.

With high temperatures forecast to continue through August and beyond, especially in western Japan, the JMA is calling on people to take appropriate precautions against heatstroke.

Data Sources

(Translated from Japanese. Banner photo © Pixta.)