dog days

The phrase "dog days" originally refers to the hottest period of the year, usually occurring between early July and early September in the Northern Hemisphere. It is believed to derive from the ancient belief that the position of the Dog Star, Sirius, in the constellation Canis Major, had a correlation with the summer heat. In modern usage, "dog days" can also represent a period of stagnation or inactivity often associated with the hottest part of summer.