Spring constellations are the constellations that are best seen in the evening night sky from late March to late June in the northern hemisphere and from late September to late December in the southern hemisphere. The most prominent northern spring constellations are Ursa Major, Boötes, Leo, Cancer, Virgo and Hydra. For northern observers who can see these constellations, spring is the best time of year to observe them. Summer constellations are the constellations that are best seen in the evening night sky from late June to late September in the northern hemisphere and from late December to late March in the southern hemisphere. There are several prominent constellations that dominate the summer sky. For northern observers, these are the three constellations whose brightest stars (Altair, Deneb and Vega) form the Summer Triangle – Aquila, Cygnus and Lyra which can be an interesting sight to see.