General Comments:

This manuscript presents a 40-year high-resolution gridded meteorological dataset for the Reynolds Creek Experimental Watershed in southwest Idaho, USA.  This watershed is designated as a Critical Zone Observatory and is located in the rain-snow transition zone and snow-dominated semi-arid environments, which have experienced shifting due to climatic change.  The manuscript describes how the high-resolution gridded dataset was developed from weather stations in this watershed. The presented dataset is extremely important to climate change, hydrology, and ecology related research and can make contribution to understanding climatic change response in the rain-snow transition zone.  In addition, the dataset is valuable forcing data for hydrologic model benchmarking and development as well as validation data for atmospheric reanalysis model outputs. The dataset stored in the data repository mentioned in the manuscript meets the standard of usefulness and completeness and can be readily accessed and extracted in the methods described in the manuscript.  Overall, the manuscript is well written and easy to follow and should be acceptable for publication with minor revisions.  I have a number of specific comments and technical corrections below for authors to consider.

Specific Comments:

1. In Figure 1, the red box weir number, i.e., 135 appears in the inset map of Johnston Draw sub-watershed, while the weir number 135 is for Dobson Creek sub-watershed. I suggest authors move the red box 135 out of that inset map and place it in the main map. In addition, use a thicker red color outline for the boundary of Dobson Creek sub-watershed, as it is barely visible with the thin outline. This is same for pink color outline for Salmon Creek sub-watershed, use a thicker outline to improve readability. Also, I suggest authors perhaps include an inset map showing the location of RCEW in USA for general readers who are not familiar with the watershed.
2. In section 4.2, for the relative humidity (RH), is it corrected for saturation vapor pressure over ice when air temperature is below freezing? Same comment for vapor pressure, the Eq. 1 shows vapor pressure estimation when air temperature is above freezing, does the vapor pressure estimation consider when air temperature is below freezing? Air temperature can drop below freezing in the RCEW, and perhaps authors can add some clarification for this in this section.
3. In section 5, the description for mean elevation of mixed phase precipitation (e.g. grid cells where -1°C < T_wb <1°C), is this different from the definition of mixed precipitation shown on Line 216: “When time step precipitation temperatures fell between -0.5°C and +0.5°C, the precipitation was defined as mixed phase,”? Please check this and use the consistent definition for mixed phase precipitation.

Technical Corrections:

1. Based on the notation for date and time by the journal, please use the following corrections:
   1. Line 7: please change “water years 1984 to 2023 (October 1^st to September 30^th)” to “water years from 1 October 1983 to 30 September 2023”.
   2. Line 94: please change “for the time-period October 1, 1983 - September 30, 2023.” to “from 1 October 1983 to 30 September 2023”.
2. Line 77: please change “(where a water year is defined to begin on 1 October and end on 30 September)” to “(a water year beginning from 1 October to 30 September of the following year)”.
3. Based on the notation for hyphen by the journal (i.e., recommend not to hyphenate modifiers containing abbreviated units), please change “10-meter” to “10 m” for the following corrections where “10-meter” appears: Line 9, Line 45, Line 65, Line 83, Line 102, Line 112, Line 122, Line 138, Line 154, Line 155, Line 201, and Line 256.
4. Please add hyphen between sub and watershed or watersheds, that is, use the “sub-watershed” or “sub-watersheds” for the following corrections: Line 68, Line 222, and Line 236.
5. Line 16: please remove “and” before uncertainty analyses.
6. Line 21, please add a comma before yet. Yet is used as conjunction.
7. Line 31: please change “ranging between 1-4 km²” to “ranging between 1 and 4 km²”.
8. Line 35: please remove “or” before due to.
9. Line 49: please use “maximize” to have consistent English style (i.e., American English) used in the text.
10. Line 54: please use lower case “southwest” to be consistent with ones used throughout the text.
11. Line 57: please remove “exists”, the verb is not needed.
12. Line 58 to 59: please change “from 228 mm at site RC.057 in the low northeast elevations to 1,086 mm at site RC.163 in the highest southwest elevations of the watershed” to “from 228 mm at site RC.057 in the lowest elevations to 1,086 mm at site RC.163 in the highest elevations of the watershed”. This is to improve clarity, as lowest and highest are for entire watershed, not lowest in northeast and highest southwest.
13. Line 61: please change “This dataset updates the gridded temperature, humidity, and precipitation dataset” to “This dataset updates the gridded air temperature, relative humidity, and precipitation dataset”.
14. Line 62: please remove “of conditions” before (2015-2023).
15. Line 73 to 74: please shorten “maintained by the USDA Agricultural Research Service (ARS) Northwest Watershed Research Center (NWRC)” to “maintained by the USDA-ARS-NWRC”. The organization abbreviation has already been described in section 2, so the abbreviation can be used in this section.
16. Line 110: please use “in degrees Celsius”. The unit for air temperature in Tetens equation should be degrees Celsius.
17. Line 123: please combine references as “Winstral et al. (2002, 2009). Also, these two papers are not presented in the reference list, please add them.
18. Please use consistent verb tense with other sections in the text and have the following correction:
    1. Line 123: “the underlying digital elevation model (DEM) was”
    2. Line 125: “resulting 72 layers of maxus grids were stored in a lookup library”
    3. Line 126: “measured wind speed was adjusted to”
    4. Line 128: “had been distributed across the entire grid using standard IDW, the distributed wind directions were used to find the maxus value”
    5. Line 129: “the distributed ‘flatwind’ speeds were converted back to”
    6. Line 135: “Gridded incoming shortwave radiation (Sin) was measured at 23 sites”
    7. Line 146: “Diffuse shortwave radiation under canopy (Rd) was computed by”
19. Please add a comma for better readability on Line 126 and Line 129, as the following:
    1. Line 125 to126: “for each station, the measured wind speed”
    2. Line 128 to 129: “the distributed wind directions were used to find the maxus value for each grid cell, and the distributed ‘flatwind’ speeds were converted back to actual wind speeds”
20. Line 138: for better readability, please change “Hourly clear sky atmospheric Sin was modeled, then corrected for surrounding terrain in each 10-meter grid cell following Dozier (1980) and Dubayah (1994), respectively.” to “Hourly clear sky atmospheric Sin was modeled following Dozier (1980) and then was corrected for surrounding terrain in each 10 m grid cell following Dubayah (1994).”
21. Line 149: please remove “then” before the sum of.
22. Line 153: please remove “the” before τ, μ.
23. Line 156: please change “well-represented” to “well represented” based on the notation for hyphen by the journal.
24. Line 171: please remove en dashes (–) before or instruments and before for periods.
25. Line 179: please use lower case “the” before RCLT.
26. Line 192 to 193: please change “the RCEW measurement network was initially planned to contain one gauge for every square mile of the watershed (n=110)” to “the RCEW measurement network was initially planned to contain one gauge for every square mile and 110 stations for the watershed”.
27. Line 194 to 195: “used here to produce the hourly gridded precipitation fields (Figure 1).” Figure 1 does not show the precipitation fields, please refer to the correct figure if it is presented in the paper.
28. Line 196 to 197: please change “was used for all but one of the sites in the RCEW” to “was used for all sites in the RCEW except for RC.124B”.
29. Line 201 to 202: please change “using a Detrended Kriging interpolation method (Garen, 1995) identical to the approach by Kormos et al. (2018)” to “using a Detrended Kriging interpolation method (Garen, 1995), which is identical to the approach by Kormos et al. (2018)”
30. Line 207 to 208: please change “Prior work has demonstrated that wet bulb temperature is the most suitable method for partitioning snow from rain in a semiarid watershed such as the RCEW (Marks et al., 2013).” to “Previous research has demonstrated that wet bulb temperature is the most suitable precipitation phase partitioning method in a semiarid watershed such as the RCEW (Marks et al., 2013).”
31. Line 210: please remove “accumulated” before snow density.
32. Line 217 to 2018: please change “and warmer temperatures were 100% rainfall” to “and warmer temperatures produced 100% rainfall”.
33. Line 221: please change “For an example demonstrating the utility of this unique dataset we examine how the annual average storm-based” to “As an example of the utility of this unique dataset, we examined how the annual average storm-based”.
34. Line 228: please change “The accumulation season was defined as the period prior to peak SWE accumulation” to “The accumulation season was defined as the period from 1 October to peak snow accumulation (SWE)”. This change also defines the SWE abbreviation used subsequently.
35. Line 230 to 231: please change “the RS_z has risen from 1,830 meters in 1984 to 1,991 meters in 2023 and resulted in a decrease in snow-dominated basin area from 52% to 24%” to “the RS_z has risen from 1,830 meters in 1984 to 1,991 meters in 2023, resulting in a decrease in snow-dominated basin area from 52% to 24%”
36. Line 236 to 237: please change “snow accumulation season (October 1 – peak SWE date)” to “snow accumulation season (from 1 October to peak SWE date)”.
37. Line 247: please change “ snow dominated” to “snow-dominated”. This is to be consistent with style used throughout the text.
38. In Figure 5a, the fit lines for trend analysis of rain/snow transition elevation are shown in orange line and navy blue line for all storms and accumulation season storms; also, there are two gray dot lines shown for the elevation ranges of Tollgate sub-watershed. Perhaps, to help readers, add these fit lines and dot line in the legend or describe them in the figure caption.

This compact paper describes a rasterized dataset of meteorological variables with high spatial and temporal resolution for the Reynolds Creek Experimental Watershed (Idaho, USA). The dataset was derived from operational station measurements using various spatial interpolation and modeling techniques and is available for download. It provides a valuable basis for a wide range of potential quantitative investigations of processes in the atmospheric boundary layer and land surface hydrology, particularly snow hydrology, for which the dataset was originally developed.

The paper is written in very good English and is a pleasant read. I agree with all the comments and suggestions for improvement made by the first reviewer (RC1); these have obviously been incorporated into a second version of the manuscript (which, however, is not available to me). From my perspective, only a few minor points remain that I would address prior to publication of the manuscript.

What would be desirable is a paragraph about the code (which is also available) used to calculate the new dataset. Would it be possible to use this code to generate a comparable dataset with, for example, lower spatial (e.g., 100 m) and temporal (e.g., 3-hourly) resolution, or to apply it to a different area? It would be an additional benefit of your paper if you write a few explanatory sentences about this in a short dedicated paragraph.

Minor technical corrections and revisions for improvement:

86: „ … differing levels of accuracy, which are not reported here“: Could you at least provide some basic experiences by the „full-time staff of technicians tasked with the calibration and servicing of each sensor deployed in the RCEW“ to give the user of the dataset an idea if the station recordings of a certain variable are less or more reliable? Are the types of sensors used documented somewhere (if yes, a reference would be helpful)

Figure 2: I would recommend to extend this table with the units of the single variables and with their very basic statistics (e.g., annual min, mean, max for the 4 decades covered?)

Figure 3: the x-axis does not show the period covered by the data. Can you adjust it as true time line so that it correctly covers the time-period 1 October 1983 - 30 September 2023 with correct length of months and years, ticks positioned at the beginning/end of a year, and year inscriptions positioned between these ticks?

Figure 4: again, the x-axis should be a true time line and add the day to the given year/month

Figure 4/caption: „... observed versus modeled maximum daily incoming solar radiation (Sin) at three sites …“

4.6.3: Density of New Snow: can you at least say what new snow densities the lookup table approach produces for typical snowfall conditions in the RCEW?

4.6.4: does „mixed phase“ precipitation mean that certain fractions of snow/rain occur, depending on precipitation temperature between -0.5°C and +0.5°C? How is the transition shaped?

Fig. 5a in the legend: „Accum season storms“: better do not abbreviate. Again, convert the x-axis to a true timeline (see comment to figure 3).