Overall, this manuscript examined the heatwaves of eastern European using long-term observation datasets. One important finding of the manuscript is to identify the importance of long-term observation data to reveal the "real" trend of heatwaves. Another important finding of the study is to reveal the correlation of heatwave and AMO. Overall, i find this paper well-written, and reads smoothly and I really enjoy reading it. Besides a few minor typos, I suggest acceptance of this manuscript. Detailed comments are listed below. 

1. In the title of the paper it mentioned "the role of natural variability vs anthropogenic factors". However, after reading the entire manuscript, i don't seem to agree with the title, as there is little about quantification of the contribution of natural and anthropogenic factors to heatwaves, such as that in Luo et al. (2023). Therefore, i would recommend either delete it, or use something else. 

2. Line 112. should be "Which is an indicator"

3. Line 207, "which can be influenced"

4. Line 243, "indicates how difficult", i would suggest using "misleading" instead of "difficult" here

5. You may consider adding few more references here. 

Lau N-C, Nath MJ (2012) A model study of heat waves over NorthAmerica: meteorological aspects and projections for the twenty-first century. J Clim 25:4761–4784. https://doi.org/10.1175/JCLI-D-11-00575.1

This paper examines the Eastern European heatwave of 2023 from a long-term perspective. The article selected many extreme heat wave periods in history that were accompanied by similar weather conditions and explained the high-temperature variability well through analysis.  Overall, this work is very meticulous, by combining weather scale and climate scale analysis. I suggest minor revisions. Here are my detailed comments. 

1. It would help if you highlighted how to quantify the role of natural variability and anthropogenic factors in this paper, especially in the abstract and method part.

2.  Please provide the full name of GHG

3. What do the colors of the columns (bars-from yellow to black) in Figure 2 mean?

4. You have used many indicators to represent heat waves, but not all indicators are introduced in the methods section.

5. I noticed that the ground stations you used in the Figures (Fig.2,4, 5, 6...) are not consistent.

6. I don't know what specific ERA data you are using, please use the official data name (Thermal comfort indicators derived from ERA5 reanalysis or ERA5 hour data on pressure levels from 1940 to present) instead of ERA_ heat. 

7. What do the sticks in different colors below the yticks refer to?

8.  Heatwave or HW needs to be consistent.

9. In Fig.9, some subfigures show the study area, but some do not. Please be consistent and introduce it.

10. I can't understand subgraph (a) in Fig8-10. The  detailed information is not mentioned (i.e. green line, red area not fully displayed)

11. Line 155: I'm not sure if your citation method is correct, please check.

12. Line 311: please introduce the location of  " Carpathian Mountains".