How does Google search know my location even though I've turned it off in all of the settings?

As the title says - doesn't matter what web browser I use on my Desktop PC, **even though I'm logged out of my Google account**, if I do a Google search it always accurately displays my location at the bottom of the search window. I'm mostly using Firefox as my browser.

Could it be related to my smartphone? That of course has GPS enabled as I use it from time to time, although I rarely use my Google account on …

google google search location privacy search settings