This manuscript aimed to establish a chronology of local climate disasters over the past 400 years in central Japan based on Oxygen isotope ratios (δ18O) of tree-ring cellulose together with historical documentary records. The δ18O record is derived from a long-living cedar tree with wide rings. The authors separated each ring to six segments to present sub-seasonal δ18O variations. Correlation with climate factors showed that he intra-ring δ18O variations of the sample tree reflected the hydroclimatic conditions from April to July of each year. Together with historical documentary records of drought and long-rain years, they complement those climate disaster record and provide a more detailed chronology of drought and long-rain chronologies since the 17th century in Central Japan. This manuscript is well structured and written. This manuscript could be accepted after considering some points where I have some doubts about what has been done.

Specific comments:

My major concern is that the authors conducted this research based on only one tree sample. It is fortunate their intra-annual tree-ring oxygen isotope ratios shows similar variability with a chronology built by Nakatsuka et al. (2020).

The authors wrote: Nakatsuka et al. (2020) conducted a study on the long-term variation of the climatological component of tree-ring δ18O in Central Japan. Their resultant chronology was compared with the annual-averaged δ 18O chronology of this study (red line in Fig. 4b). These two chronologies showed similar long-term variations for almost the entire measurement period of this study. A significant positive correlation was also observed, r = 0.53 (n = 396, p < 0.01).

It would be much better that the authors add a figure showing the comparison between the two chronologies.

Lines 149-150: the authors wrote: the 4th to 6th segments in drought and 1st and 5th segments in long rain were significant (p<0.05), and so was the 4th segment in long rain (p<0.10). It is hard to understand.

Lines 204-205: It is not very clear how the mean precipitation for drought and long-rain years extracted by the intra-ring δ 18O data in 1701–1900 are reconstructed.

From Figure 4a, it is clear that during 1700-1900 AD the annual ring is divided into 6 segments for each year. So, I would suggest the authors clarify the variation of number of segments clearer in the text and figure captions.

Lines 220-224: it should be moved to Section 3.4?

Figure 6: How is the deviation calculated?

The authors wrote: The mean value and standard deviation of δ18O for each segment for each of the years of long rain, drought, flood, and famine are shown in Fig. S1. However, I did not find any content with regard to standard deviation.

This article is academically sound. It compared tree ring chronologies with historical documentary records. The idea is unique and very interesting. Both tree ring and documentary records are major sources of historical climate studies, but few studies carefully compared these two sources.

The analysis is reliable and the results are persuasive. I believe that it should merit publication in EGUsphere after a few modifications.

My suggestions are as following,

1. Apart from the records about precipitation, the documentary records about temperature could also have affected δ18O of tree ring, e.g., abnormally hot or cool growing seasons (including summer, spring and autumn), cold waves in growing seasons (unseasonal frosts and snow).

2. Insect damage is another type of factor; it would be better to analyse it separately.

3. Sometimes, local environmental change and incidents in the vicinity of the sampling sites could affect the tree rings. It would be better to exclude these effects.

I concur with the recommendation and comments made by the first referee. In addition, I would like the authors to also address the following comments or questions:

1. Please provide the necessary details of the historical documents. For example, where the 20 cities/towns are actually located? How is a disaster defined and recorded (by examples)? What is the difference and connection between long rain and flood? Are there descriptions of connection between drought/long rain with famine in the original record? 

2. The quality and reliability of the historical documents needs brief validation, including its comparison to documents from other regions, and application in previous investigation.

3. Please provide the scientific rationale of dividing the annual tree-ring sample into six subsamples. The same applies to the association between the delta O18 results in the subsamples and the 10-day relative humidity and precipitation.

4. The scientific significance of this study needs to be made clearer. For sample, the authors mention in the conclusion that

"The range of δ18O variation within an annual ring was generally larger than that of inter-annual variation (Fig. 4b), which indicates that substantial information originally contained in tree-ring δ18O variation is obscured in annually-measured tree ring δ18O data."   

Then what contribution does this study offer if its drought/long rain chronologies also only have annual resolution? 

5. The conclusion would benefit significantly from including a paragraph discussion the implication of its results, for example, the drought/long rain chronologies in the broad field of climate research.