Tokyo, Osaka and Nagoya reached 30 C (86 F) or higher on Wednesday, Oct. 21, setting records for the latest such day of the year, the Asahi Shimbun and AFP reported.

Central Tokyo hit 30.3 C, Nagoya 31.4 C and Osaka 31.2 C by 3 p.m. local time, the Asahi Shimbun reported. The paper said warm air from a Pacific high-pressure system caused the unseasonable heat along the Pacific coast.

The Japan Meteorological Agency calls a day of 30 C or more a "midsummer day." Kazuhiro Shirono, a data official at the agency, said Tokyo's mark was the latest such day since records began in 1875, AFP reported.

The previous latest date in central Tokyo was Oct. 19, 2024, the Asahi Shimbun reported, citing the agency. Osaka's old record was Oct. 20, 1933. In Nagoya, the old mark was Oct. 17, set in both 2024 and 1961. Osaka began keeping weather records in 1883, AFP said.

Other parts of Japan were even hotter. As of 3:10 p.m., Hyuga in Miyazaki Prefecture had the country's highest reading at 33.6 C, the Asahi Shimbun reported. Kofu reached 33.5 C, and 155 places hit 30 C or more by 3 p.m.

Scientists say human-caused climate change is making extreme heat events more frequent and more intense around the world, AFP reported. Japan had its hottest summer on record in 2025.

This year, the weather agency began using a new word, "kokushobi," meaning "cruelly hot day," for days that reach 40 C (104 F), AFP reported. The agency has urged the public to treat extreme heat like a natural disaster.

The Asahi Shimbun said many people walking near the Imperial Palace in Tokyo were wearing short sleeves on Wednesday.

What we know: Tokyo, Osaka and Nagoya all set records for their latest 30 C day of the year.
What we don't: How long the late warm spell will last in the coming days.