Precipitation events from March 1 to 7 are analyzed in the Aso region, central Kyushu, based on local traditional event known as “Noyaki” (controlled burning), held on the first Sunday of March, which has been postponed in recent years. During the period 2002-2009, precipitation was not observed on the first Sunday of March at the Aso-Otohime Station of the Automated Meteorological Data Acquisition System (AMeDAS), whereas it was frequently observed during the period 2010-2021. The number of rainy days from March 1 to 7 at AMeDAS stations throughout Kyushu during the period 2010-2021 was greater overall than that during the period 2002-2009, with a statistically significant increase confirmed at eight stations located in the eastern–southeastern part of Kyushu. Precipitation from March 1 to 7 increased throughout Kyushu, with the exception of the northern part during the period 2010-2021, whereas the intensity of precipitation did not show any statistically significant change at the AMeDAS stations as a whole. Therefore, it is considered that the increase in rainy days is responsible for the frequently observed rainfall and the increase in precipitation around the Aso region during the period 2010-2021. From the run test, it is concluded that there will be regularity in the series of the presence/absence of precipitation at AMeDAS Aso-Otohime Station in the future, whether or not there is precipitation on the first Sunday of March. When precipitation persists, regularity emerges, suggesting a long-term increasing trend in the increase of precipitation events, while the absence of precipitation suggests that the recent increase in precipitation events is a component of cyclical variations.
