Japan experienced its warmest September on record in 2023, with a national monthly temperature that was 2.66 °C (4.79 °F) higher than the standard. The record-breaking temperatures were particularly pronounced in the eastern and western regions of the country.
In September 2023, Japan recorded its hottest September in history, as confirmed by the Japan Meteorological Agency (JMA). The national monthly average temperature for September was 2.66 °C (4.79 °F) above the norm, greatly surpassing the previous record for September of 1.51 °C (2.72 °F) set in 2012. Notably, eastern and western regions of Japan also experienced their warmest September since records began in 1946.
The JMA characterized the extreme September temperatures as “unbelievably very rare.” The unusual heat was distributed across the country, but it was particularly intense in the eastern and western regions. In eastern Japan, the monthly average temperature anomaly for September was +3.1 °C (+5.58 °F), while it was +2.3 °C (+4.14 °F) in western Japan.
The Pacific side of western Japan witnessed lower-than-usual levels of precipitation in September, as it was less influenced by fronts and cyclones. This dry condition also contributed to the elevated temperatures.
In addition to the atmospheric temperatures, sea surface temperatures near the Japanese coast reached record levels for September. The confluence of these factors resulted in an unusually high national monthly average temperature for the month.
1 Japan monthly weather – September 2023 – JMA
Featured image credit: JMA
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