Historical Documents

Weather diary records since the 18th century

In Japan, a large number of weather diaries from most parts of the country are preserved in local libraries and museums. Some outstanding official diaries have been kept continuously since the seventeenth century. Over the last few decades, most of the known daily weather records were digitized and added to the Historical Weather Database of Japan (Mikami, 1988, 1999). Based on these daily weather records, it should be possible to estimate the amount of precipitation, the seasonal mean temperature and even to reconstruct typical pressure patterns which are relevant to regional precipitation distributions (e.g. Mikami, 2008; Hirano and Mikami, 2008).

An example of daily weather descriptions in old diaries : “Hirosaki-han Edo” Diary (Hirosaki City Library).