Primarily, there are two reasons why the location information provided by Google is not reflected correctly:
The first step at resolving the issue is to sign out of the Gmail account. Then, clear your browser's history completely for all time and against all parameters. After doing so, perform a generic Google search and and see if the location details have corrected.
The other reason why there could be a location mis-match is due to bad or stale IP geo location information. After extensive tests in combination with user reports, it seems like Google has their own IP geo location database. Therefore, in order to the bottom of the matter, you can check the IP geo location details via iplocation.net.
The information offered by iplocation.net tends to reference the most commonly used IP geo location databases. If the IP geo location databases are providing the correct information but Google is not then, it is most likely an issue with Google.