Dalmatian, I strongly disagree that your climate can be compared to that of California, and neither mine who am more south than you.
First of all California itself has a range of different climates, and also if we only consider the coasts, there are three main area to consider (south-central-north). Apart from this, while min temp can be compared, the difference in latitude must not be set aside. Let me try to explain.
The point is that our Mediterranean sea acts as an insulator thus keeping the low temp very mild. In the Usa this doesn't happen. Just consider that the typical frost that you have (around 0 to -3 degrees) occurs in California down to San Diego, which is much lower than you are in latitude. In other words you are maybe around 43-44 of latitude, and you have frosts of such a mild intensity that can be compared to areas of the USA much more south in latitude. Me for example, I am at latitude 39, which corresponds barely to the north tip of California, but my region's min temp are infinitely milder than north California, much milder than central California, and almost equal to far south California. However there are in my region also areas totally frost-free which can rarely be found in Cali also in the south. Discussing for example with Richard we found that my hillside's min temp are not far different from his San Diego location, even if my hillside location is at 560 m of altitude and 20 km from the sea. So my coast compared to San Diego coast is milder. Many other examples could be taken, as the south of Texas or south Arizona where at very low latitude the min temp are similar to my hills' location, and cooler than my coast (with the exception of the rio grande valley which is almost equal to some coastal areas here). Moreover, all these areas have periodical critical freezes which are rare in the Mediterranean. For example all the rio grande palm vegetation was destroyed to the ground after the 83 and 89 historical freezes, where entire days under the 0 (ice days) where recorded, a thing which in the Mediterranean never occurs not even at higher latitude (like the French coast or you area).
However, this is only half of the story.
If min temp are determined by various different factors, much more the difference of latitude can be perceived on the max temp. The max temp they have in San Diego, in Corpus Christi, in Phoenix, Houston, etc are much different than ours, and this especially in winter. This has a great impact on many plant's resistance to cold. In fact, it is usually easier for certain sub-tropical trees to recover from a slight night frost if the day-after daily temp reaches 18-20 as usually happen. In other cases it is just the contrary, because plants (especially bananas) don't go sleeping because of high daily temp and then can be more easily frozen by night frost. But all in all, high temp are a relevant factor which must be considered. The summ of all this is that very simply the conditions are different, and while a comparison is useful, and me myself I try to compare to search the best plants to grow, it cannot be stated that the climate is almost equal, as you said.
A friend here answered about his winter temp. Observe that while the min temp can be similar or equal to yours, this cannot be said of max winter temp. He said daily temp of 15-20. You cannot have these temp in Croatia. Of course here also we have 16-18 in Jan and Feb, but 19-20 is a rare event and I am more south than you. Here also it happens to have days in the 12-15.
These points I had to made them clear because you cannot base you chances on comparison whith such different climate. But it doesn't mean you cannot grow anything. You can grow a lot of things, I think, at least if your min temp are taken from official sources. I want to give some suggestions on things that are more easy for you to grow:
- Avocado, varieties Zutano, Mexicola. Also the Hess and Ettinger can be tried. Usually the Hess has Bacon as pollinator, but it's only half necessary.
- Annona. variety Fino de Jete, only if you have as record low no more than -3. Basically if lemons grow outside unprotected.
- Papaya is very difficult to grow. In any case you need heavy winter protection or grow them in pot and winter recovering. But you can try Babaco (carica pentagona) and Carica quercifolia (which has very small fruit but is very hardy).
- The best mango varieties in Mediterranean conditions seems to be Kensington. However at your latitude you will still need winter protections and much care. I am not sure youcan grow it but you can give a try. The same applies to litchi.
- Passiflora, especially the purple-fruit. You should plant it near a wall where it can climb. The wall will act as insulator.
There are many other things you can grow depending on your will. We can continue the discussion if you have particular clues.