The Dog Days of Summer
1 : the period between early July and early September when the hot sultry weather of summer usually occurs in the Northern Hemisphere
2 : a period of stagnation or inactivity
The brightest star in the constellation Canis Major ("the big dog") is Sirius. It is also the brightest start in the night sky. In the summer Sirius rises and sets with the sun. The ancients believed that the heat of the "dog star" added to the heat of the sun thus creating a stretch of hot and sultry weather. Thus, the 20 days before the conjunction between the sun and Sirius to 20 days after were called the "dog days." The Dog Days of Summer occur between July 3 and August 11 this year.
Old Girl II by Andrea Mackey