What are “dog days”?

“Dog days” are the hot, humid days of summer that usually take place in the Northern Hemisphere in July and August—typically between July 3 and August 11. The days get their name from the dog star Sirius of the constellation Canis Major. At this time of year, Sirius, the brightest visible star, rises in the east at the same time as the Sun in the northern hemisphere. Ancient Egyptians believed that the heat of this brilliant star added to the Sun’s heat to create this hot weather—and they blamed the star for everything from withering droughts to sickness.