General comments

The preprint is well written, clear and concise. It covers all the points I feel are necessary to describe this dataset. Scientifically, it is an important dataset and ESSD is the correct forum to present this record. Fritz et al. introduce a new precipitation isotope dataset from Inuvik, NT Canada, developed from 134 precipitation event samples collected from August 2015 to August 2018. The new sample size dwarfs the previous record available for this area (e.g., the original Inuvik record was defined by 14 monthly observations from the late 1980s). More broadly, the network of precipitation isotope records in the Canadian Arctic is very sparse in space and time, and badly out of date. Despite these limitations/uncertainties, Arctic precipitation isotope data have played critical roles in guiding the interpretation of environmental isotope datasets across a broad spectrum of research disciplines in paleoclimate (e.g., Porter et al., 2019, Nature Comm.; Holland et al., 2020, Geophys. Res. Lett.), cryosphere (Mackay, 1990, Can. J. Earth Sci.; Lacelle et al., 2014, Chem. Geol; Bandara et al. 2020, Permafr. Periglac. Process.) and hydrological sciences (Turner et al., 2014, Glob. Change Biol), and many others. However, the existing high-latitude precipitation isotope network including key stations such as Inuvik is now badly out of date, and the extent to which these old data are representative of modern precipitation-isotope systematics *was* (before this study) unclear after so many decades of change in climate and boundary conditions. Inuvik is major research center in the Canadian Arctic that invites hundreds of researchers from around the world each summer. A major update to the Inuvik isotope record was long overdue. This contribution will help advance our knowledge of local to regional precipitation-isotope systematics, which, in turn, will benefit an international and interdisciplinary community of researchers who are focused on the NW Canadian Arctic. I look forward to seeing this paper published in ESSD. I have only minor comments for improvement listed below.

Specific comments/questions

L40. What is meant by ‘tackled by’? Clarify in simpler terms.

L59-61. This is a long sentence. Break it up if possible. I would also recommend elaborating on the significance of the Inuvik station. Inuvik is one of the most important centers of research in the NW Canadian Arctic.

L86-88. It seems very reasonable to exclude only one sample, but you should still explain *why* it should be excluded. Describing it as ‘unusual’ is ambiguous. Please be more descriptive.

L96. Table caption, suggest revising to: Summary of precipitation events by month and year.

L99. “During this 4-year period only 14 monthly observations of d2H and d18O are available.” Or something like this. Current sentence is a bit confusing.

L135-136. Porter et al. (2016, QSR – see Fig. 3b) also demonstrate higher d-excess during winter (colder) months across the broader Arctic GNIP network.

L141. Can you elaborate? Also, I do understand that whether or not the old vs. new LMWL is not very important. This is an important data contribution. However, since you are comparing old vs. new LMWL’s, you might consider a t-test based on +/- 1 sigma of the slope and intercept.

L144-145. In this caption, add the n=34 and n=14 inside the brackets with the years.

L156. See comment about L141. Is this difference significant? If the difference is significant, probably the most important reason is that the old LMWL is defined by very few data points and may not be so representative. I think the following discussion in this paragraph is good, but you might try to simplify the sentences a bit. And please add a clear statement that the new LMWL is likely a better characterisation of local precipitation isotope dynamics that the old LMWL, simply on the basis of greater sample size.

L158-161. Sentence is too long. Please break it up into smaller, more readable sentences.

Technical corrections

L23. Use proper multiplication symbol.

L39. Improper use of semi-colon. Please revise the following sentences.

See the attached file.

This data description paper by Fritz and co-authors presents a very useful data set which covers a data gap in high latitude precipitation at Inuvik over recent periods. Having isotopic data from high latitude stations is always a difficult task but of paramount importance when we look at past and recent climate changes in the Arctic. The paper accompanying the data is well written and well structured.

I have only few minor comments/questions regarding the quite negative deuterium excess values, the sampling procedure, and the way the mean monthly values are calculated. I would like the authors to comments on these points.

• Negative d excess values: I noticed in the data sets that quite negative values are present, mostly (BUT not only …) centred during summer months. Can you exclude evaporation effects? Are those samples properly preserved/collected?
• Regarding the sampling procedure: how did you perform the snow sampling? Usually collecting snow, it is not an easy task, particularly using the “normal rain” collectors. It was not clear in the text.
• How did you calculate the mean monthly values? Is this an arithmetical mean or you averaged out the values considering the precipitation amount? This is quite important since you then use the monthly data for the LMWL.
• Adding the precipitation amounts, if available, could be an interesting information, although I can understand that this request could be not satisfied.

May you add in Table 3 the elevation of the different stations?