特とく異い日び

noun

singularity day; statistically anomalous weather day

A technical term in climatology for a calendar day on which a specific weather phenomenon (e.g., heavy rain, clear skies) occurs with a statistically significant frequency compared to surrounding days. Often used in Japanese weather folklore and meteorological statistics.

• 11月がつ3日かは晴はれの特とく異い日びとして知しられている。

  November 3rd is known as a singularity day for clear weather.

• 気き象しょう庁ちょうのデータによると、この日ひは雨あめの特とく異い日びだ。

  According to the Japan Meteorological Agency's data, this day is a singularity day for rain.