Almost every WiFi hotspot (including your house) has a location associated with it. Google, FB, etc know where you are within 300 feet, just by the fact you are connected to a known WiFi location. Furthermore if you leave WiFi turned on, you don't even have to connect to a hotspot to provide location data. The fact that your device saw the hotspot creates a breadcrumb trail of time and location.

I'm not wearing a tinfoil hat in my underground bunker while typing this, I do however have a decade of experience in the computer industry, most of it within product development. Trust me, The Google knows as does Facebook and any other app you have.

Another point to ponder WRT Facebook, Google, etc. It the service is free, you are the product, not the customer....