The nights are getting longer as we enter September, and there is less time to wait after sunset for true darkness. But the summer sky, particularly the southerly parts in Sagittarius is disappearing; catch it while you can. The areas further north in and around Cygnus will be with us for a while yet.
September is also the obvious month for having a look at Neptune. At Magnitude 8, and just 2″ in diameter, it is never an easy object. Nor does it help that it is lurking 10 degrees south of the equator in Aquarius, quite an obscure constellation SW of Pegasus, with no star brighter than magnitude 3. This means that finding it by star hopping requires patience, and good transparency. The star map below may help.
Neptune is in the middle of the map, roughly in the middle of the diamond shape formed by iota, theta, lamda, and tau, and about a degree north and a little east from 5th magnitude sigma. Worth a try. It should be identifiable by position, and a reasonable sized telescope should show that it is more than a starlike object.
Looking for, and at , Neptune, is also good preparation for Uranus, coming to opposition next month, as Uranus will seem bright, large, and well placed by comparison!