Step 1 : Introduction to the question "When do the "Dog Days of Summer" arrive?"
...The phrase "Dog Days of Summer" is not actually a shout-out to the beloved family pet, but rather is a reference to Sirius, a star that's part of the constellation Canis Major, or the Greater Dog. During the Dog Days, the sun occupies the same area of the sky as Sirius. Also called the Dog Star, Sirius is the brightest star in the sky visible from any part of the Earth. These Dog Days of Summer roll around each year between July 3rd and August 11th. Although some would argue that the weather during this time is "not fit for a dog," all agree that it's the most oppressive period of summer's heat. Source: FarmersAlmanac.com