According to NASA, there is much to see in the night sky this month including, Mars, a "red triangle" with bright red stars, Saturn and Jupiter!
MARS: You can see Mars in the sky during September mornings. Look to the south about one hour before sunrise. Over the course of the month, Mars works its way eastward from orange-colored Aldebaran toward reddish Betelgeuse, creating a sort of "red triangle" in the morning sky. Then the red planet will appear to hit the brakes and halt its eastward motion to hang out in that triangle for roughly the next month!
FULL MOON: The moon becomes full on Friday night with peak illumination at 5:58 am Saturday. This full moon is known as the harvest moon, because it is the closest full moon to the start of fall (this means sometimes the October full moon is called the harvest moon). Unlike other full moons, this full Moon rises at nearly the same time for several evenings in a row.
JUPITER AND SATURN: By the morning of September 11th, the moon will look to be only a few finger-widths away from Jupiter! Plus, Jupiter is at opposition this month and will be visible all night (per cloud cover). This is also around the time Jupiter will look bigger and brighter! If you have binoculars - you will be able to spot four of Jupiter's moons!
Saturn joins Jupiter all month long during the evenings. On Friday night (September 9), Jupiter and Saturn escort the moon across the sky. You'll find the trio rising in the southeast in the first couple of hours after dark and gliding westward together over the course of the night. By the end of the month, you'll find the pair of planets is rising even earlier, appearing in the east soon after it gets dark, with bright Jupiter hanging low in the sky!
BONUS VIEWING TIP! If you take note of exactly where the sun appears to rise and set on the first day of fall (and spring), those points mark the locations of due east and due west, respectively. That can be very useful for sky-watchers, whatever hemisphere you happen to live in. So take note of any buildings, tall trees, lampposts, and the like at those places on the horizon, and you can use them to find your bearings when looking skyward all year long.