To get the best estimate of the sky conditions in your neighbourhood you will need to survey as much of the sky as possible.
It helps if you can avoid nearby tall buildings, trees, and direct bright lighting if possible.
Of course if you live in city that may not be entirely possible, but you should still attempt to find the best site available from which to make your observations.
In suburban locations, back yards, nearby parkland, and sports fields, away from street lights and tall trees are suitable sites from which you can perform your star count. Turn off all outside lighting if possible.
The bright horizon in the lower picture is caused by scattered light from a distant city.