The constellation Draco, the Dragon, is visible in the northern hemisphere throughout the year. However, it's most prominent and easily observable during the summer months, particularly in July and August when it's high in the sky at night.

Here's why:

* Draco is a circumpolar constellation: This means it's located close enough to the celestial north pole that it never sets below the horizon for observers in the northern hemisphere.

* Seasonal variations: While always visible, Draco's position in the sky changes throughout the year. In summer, it's positioned higher in the sky, making it easier to see and trace its winding shape.

* Summer evenings: As the evenings get shorter and darker in the summer, the constellation Draco becomes more prominent against the darker night sky.

So, while Draco can be seen all year round, it's truly a summer constellation for observers in the northern hemisphere.