Pre-1872 extension of the Japanese instrumental meteorological observation series back to 1819

Official meteorological observations in Japan started in 1872. Prior to that period, from 1700 onward until 1868, daily visual weather reports are documented in diaries at many places in Japan. In this study, we have recovered instrumental observations from Dejima (Nagasaki), taken under the responsibility of the Dutch, covering the periods 1819-1828, 1845-1858 and 1871-1878. The Dejima series overlaps by six months with the modern Nagasaki Observatory series 1878-present and overlaps in its pre-1871 part with the Nagasaki 1700-1868 documentary series. The recovered data provide a means for calibrating the documentary series and extend the start of the instrumental Nagasaki series back from 1878 to 1819, leaving major gaps during 1829-1844 and 1859-1871.