This might be a very dumb question, but I love to visit places which are not very crowded. For example, I am looking for some place, preferably on the sea, to visit in the first part of September (in Europe). There are quite a few options that I can afford, but I was wondering if I could somehow find out if those places are usually crowded or not in September. Is there any way except raw Google searching to do that? I mean, I doubt there is some tool/application for that, but some tricks you might know? Or some database, something like that?
Google has a tool for this. it you search for a specific place, it will show you data Google has on how busy that place is on certain days and at certain times as a bar graph. Here is an example of the Louvre in Paris: https://www.google.com/search?q=louvre%20paris
I believe these data are gathered from Google Maps or Android users' location.
In addition, to find out similar information for a general place, like a city or region, again Google its name and in the sidabar, select "Travel Guide" and scroll down, there should be this graph to give a general indication of popular times to visit:
One caveat: I don't know if this works in all languages, but it seems to work for sure on English Google. So if it's not working, try visiting google.com and select the English language version.