The constellation Cygnus, also known as the Northern Cross, is visible in the northern hemisphere during the summer months.

Specifically, it's best seen in the late summer evenings (July to September), reaching its highest point in the sky around August.

However, you might be able to catch a glimpse of Cygnus in the early evenings of June and the early mornings of October as well.

Remember, the exact time and visibility of any constellation depends on your location and the time of year.