Weather Talk: Why are they the "dog days" of summer?

Body: 

The Dog Days of Summer are here. 

Ancient Romans referred to this stretch from late July through late August as the “dog days” because of Sirius, the Dog Star. Astronomers in many ancient cultures, including early Egyptians, Greeks and Romans, noticed the correlation between the presence of Sirius and the latter days of the summer when the heat is hard to escape.  

Sirius is called the “dog star” because it is the brightest star of the constellation, Canis Major, (The big dog) which follows Orion (the great hunter) in the night sky. This time of year, Sirius is a very bright, early morning star, which rises just ahead of the rising sun. Many ancients believed the proximity of this star to the sun, at this time of year, caused unhealthy summer weather.