You see, the star Sirius is also known as the Dog Star. For those who know the constellation Orion (which is really easy to find), if you follow the belt from right to left and continue on, your eye will likely find Sirius because it is so bright. Sirius is the brightest star of the constellation Canis Major, which in Latin means “Greater Dog.” I’m afraid that’s where the whole relationship with dogs ends – falls apart actually. But the rest is interesting nonetheless.
From the period July 3rd to Aug 11th Sirius seemingly rises in conjunction with the sun. These days are also the brightest days of sun, and Sirius is the brightest star. It is no wonder then that the ancients may have attributed the hottest summer days with the actions of the star, Sirius. The cause and effect looked accurate but was not correct.
So the origin of Dog Days comes not from the heat and humidity that makes us lethargic like a tired dog nor is it weather that makes dogs go crazy. It actually refers to movement and magnitude of the “Dog Star” and the associated summer heat as its behavior coincides with that of the sun.