Tracking Japan’s High-Temperature Days in 2026
So far, Japan’s summer in 2026 is second only to 2025 in terms of high temperatures. A look at the increasingly sweltering numbers in recent years.
As of August 4, 2026, Japan Meteorological Agency data indicates there have been 4,727 days with temperatures of 35°C or higher at their observation stations nationwide. This marks the second highest number of such days recorded this far into the year, only surpassed by the 6,144 days logged in 2025. From 2010 to 2020, only four years saw totals exceed 1,000 days by the end of July; however, since 2022, the count has surpassed 1,000 every year.
In 2026, Japan's meteorological body introduced a new term, "kokushobi" or "severe heat day," for instances when temperatures reach 40°C or higher. This extreme heat was observed at three JMA monitoring sites, including Tajimi in Gifu Prefecture, on July 21, and the Tōkai region in central Japan experienced such temperatures for five consecutive days from July 25 through July 29.
As of August 2, 2026, the cumulative total of kokushobi days stood at 27, just second to 2025's record-breaking 30 days at the same point in the year. The JMA attributes the rising temperatures to several contributing factors, including the westerly jet stream extending further north than usual near Japan, the Tibetan High pressure system over western Japan, warm air currents flowing in from the Pacific High, and the ongoing effects of global warming.
With forecasts suggesting continued high temperatures through August and beyond, particularly in western Japan, the JMA has urged the public to take necessary precautions against heatstroke.
Written by urgent.news from Nippon.com's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
