The manuscript „Oceanographic predictions of…” is an interesting study for some oceanographic predictions of water temperature for the Tallin Bay with the view of use the sea water as a renewable source of energy.

The statistic use of data is valid and show some potential for that kind of use. However I have some comments about it. These comments are as follows:

1. The title is “Oceanographic predictions…”. While there are hardly any predictions within the manuscript. There is a proper statistical explanation of the reanalysis data but without predictions for future years of months. Therefore I would suggest to change slightly the title to avoid misunderstanding. Or go further with the topic and include some predictions. It is interesting that there is an increase of the Baltic Sea’s temperatures since for example 2015/2016. Should it be categorized as a trend and can it be expected for further increase?
2. The manuscript aims to help with the planning of seawater heat pumps. However, there is very little about that kind of heat pumps in the manuscript. I suggest to add some details about seawater heat pumps technology, show some location where that kind of heat pumps works (not only are planned or analyzed) and write about some general conditions of seawater or climate.
3. Page 2, L.31: The heat pump itself can work with fluids with temperature below 0ºC (depends on technology). The problem with water in the freezing point is rather for piping and transfer system of the water.
4. Please, add units for salinity in Figure 1.
5. Figure 1 b). How much stratification in the Gotland Deep refers to conditions of the Tallin Bay considered within this manuscript?
6. Data (2.2.1) – in my opinion the short explanation of how the data was achieved is needed. Was it a general data base or a combination of independent data sets which need to be for example validated?
7. P6 L.146: Please add values od RMSD for Gulf of Finland
8. Figure 2. If the water transport originated in North Sea and transported via Danish Straits, then why grid cells were taken from the North only? And without western grid cells. Can it influence the outcomes? Figure 2 also needs some general map for location of this area.
9. Figure 4. What is point 6? Is this the location grid cell from Figure 2 or number of reanalysis data? It needs to be highlighted? In the Figure 4 there is temperature and salinity given as an average for those 6 grid cells from Figure 2 or from a certain (representative) point?
10. The analysis are provided for several depths (for example 10, 50, 70m). For heat pump technology not only this is important. Very important would be also distance from the heat pump location and the length of the piping system which will provide the water from certain depth with certain temperature. It would develop temperature difference between water from greater depths and shallower layers (or air temperature) and led to heat losses.
11. In my opinion, huge advantage of this manuscript would be to give some general statistics about air temperature in the area (for example mean monthly air temperature)
12. Figure 7. In my opinion the T>1 curve need short explanation why it ends at 50 m.
13. When considering exploitation the water of temperature about 1ºC for heat pumps some inconvenience of that solution must be taken into account. For example, there would be extraction of water of near freezing temperature in big amounts back into the seawater. Would it change the temperature stratigraphy and provide anthropogenic water mixing? Therefore the location is quite crucial for heat pump installations.
14. Figure 9. should be accompanied with the separate map (or information included in the Figure 9) about the depth where T>3,5ºC is valid.

The article complies with the good practice of scientific articles. However, there is little scientific innovation. Rather, we get updated and detailed information about changes in seawater temperature.

The title of the article "Oceanographic preconditions...", just this word "preconditions" corresponds to the content of the article. A heat engineer must answer whether the heat pump is suitable to be placed in Tallinn Bay. The article provides information for this.

I recommend publishing the article as presented