Unusual heavy rainfall in 1868 observed by J.C. Hepburn at Yokohama

Abstract

 Official meteorological observation in Japan by Japan meteorological Agency(JMA) has been established in the 1870s. Our study group has been make an effort to recover early meteorological observeation data prior to the JMA period.  We have newly recovered instrumental precipitation data series in the 1860s observed by J.C. Hepburn at Yokohama. By analyzing this precipitation data series, we found out unusual heavy rainfall
were observed during warm season of 1868. Several documentary records around Tokyo area also indicate that heavy rainfall frequently occurred during warm season of 1868.