Dear Authors,

After the revision of the manuscript, I think that it has been improved but it still suffers from major deficiencies that make it not publishable in ACP as it is. Both reviewers have reviewed again and discussed with me about the answers provided to their comments and they both agree with my statement above.
I read the revised manuscript carefully again and decided to give it one more chance providing comments mainly based to unanswered comments of the reviewers and also general manuscript problems.
In order for the paper to be published, the authors have to introduce the answers to the comments below to their manuscript and in addition, edit it again based not only on the specific comments below but in order for the manuscript to be easier and more straightforward to understand.

Trends

The lack of aerosol information before 2000 make the whole analysis weak. Especially for summer months when UV is most important to accurately know. The answers are not providing sufficient evidence that some of the calculated values are not artificial based on an aerosol climatology that is not trustworthy for the past decades. Actual AODs for model calculations after 2000 together with ones calculated with climatological aerosol versus real measurements could provide only a hint of the effect but it is still an improvement.

Unclear presentation

It is still difficult to read the manuscript and follow exactly what has been done, preciseness of language (one example: Section 2.2 and section 3.1 (see previous review #2). It is still not clear to the reader how these data are used. I think putting a short statement at the top of 2.2 saying these data were used to create monthly climatological information would help;
another one: Table 1

lack of attention to the detail and scientific interest in the material that is presented

example: strange looking features in the Coruna and Madrid time series.
The authors explain what the homogeneity tests did, but they do not at all look for reasons behind this behavior – e.g. looking into other meteo data sets of the same period could help understand the atmosphere back then and would also help convince the reader this is real)

Use of literature/main results

example section 4.14: stations from the South-Pole to Sodankyla are included when comparing the trends of this study with results of the literature -- here, it would be much more informative to try to find results that are geographically closer to the Iberian peninsula and compare those trends; also, concentrating on only statistically significant trends makes the comparison narrow, non significant trends are a result as well)

other

UVER_ob is a contradicting quantity, which is not introduced fairly straight forwardly. As pointed out, it is not clear what the interpretation of this kind of time series should be. In particular, I wonder how the quantitity would be perceived by, for example, dermatologists. Introducing such a concept would require much more discussion and motivation, including a better connection to how the information would be interpreted in the UV effects community.
In addition, in warm countries with high UV intensities it does not make very much sense to multiply the erythemal Uv dose with the open body fraction to make some statements as to possible damages to the skin. It would however make sense to compare the UV intensity (e.g. UV index) with the open body fraction in order to analyze at which periods of the year/time of the day a large open body fraction coincides with high UV intensities. Such an analysis would show when people are particularly at risk if they do not protect themselves from the sun. Within the scope of the present paper, the authors could, of course, analyze whether some changes occurred during the last years.

Eq. 15, implies that if UVER_cl_dif=0 then also UVER_all_dif=0, which is more or less self-evident. Therefore, it is a waste of space to include eq. (14) and figures based on eq. (14).

The paper needs further editing and correction of a number of minor but important issues. Most of the minor things are connected to the readability of the manuscript, the attention to detail and physical understanding/interpretation. This is an area mentioned already in the reviews, but, there was no adequate improvement in the revised manuscript.

Examples:

P2/L11: “in at least five places”, this is misleading, the number of stations starting around 1950 is five.
P3/L12: first UVER databases appeared in 1980s → it is not clear what the authors intend to say here. Also, some UV measurements were done already in the 1970s (e.g., Borkowski, 2000).
P3/L13: den Outer et al. (2010) is not an appropriate reference.
P3/L16: “other available records” is not clear, would be useful to aid the reader by defining what they are
P3/L22: SW is not defined properly
P4/L8: 0.73%/dc, how many significant digits are needed? “dc” is not defined
P4/L24: “They often attribute increased UVER radiation to ozone depletion…and to the reduction in the amount of aerosols in the atmosphere…” → Many of these papers do not specifically account for aerosol variation and therefore are unlikely to provide strong conclusions on the role of aerosols in the trends.
P5/L1: “Recently the same authors”, not clear who they are.
P5/L7: “characterized the uncertainty of these simulations caused by the monthly variability”, not clear to me what this means, what is monthly variability of inputs?
P5/L12: should the method development (two new UV reconstruction methods) not be a main motivator / objective in this study?
P7/L4-5: “direct solar radiation might not be enough to burn the dark paper card” → “might” ?
P7/L29 onward: contradicting sentence. First, all measurements are mentioned, but the end very much indicates that radiometers are in question.
P10/L6-8: From this, it seems the albedo is a monthly time series rather than a monthly climatology. Is this correct?
P10/L16-17: Not necessary to explain daily integration in this detail.
P14/L1: Why are the bins different from those in Fig. 2?
Sect. 3.2.2: would be nice to see what the reconstruction method looks like
P12/L1-4: This is interesting and basically explains why the new reconstruction method is introduced. I think this should be given more weight.

best regards

Dear Authors,
The paper can be published now, after the introduced changes.
Best regards