When are the Dog Days of Summer?

As per many people, ‘dog days of summer is a phrase stemming from the fact that dogs usually become a little lazy when the summer gets into its hottest days. It is quite obvious as they have so much fur on their bodies and tend to overheat pretty quickly. However, this phrase does not come from dogs lazing around on the scorching heat of the summer sun. The answer lies in the summer skies.

The hottest and most humid summer days were called “diēs caniculārēs” by the ancient Romans. The phrase translates to “dog days”, and it came about as the Romans linked the hottest summer days with Sirius, the star. Sirius is referred to as “Dog Star” as in Canis Major (Large Dog), the constellation, Sirius is actually the brightest star. Not to forget, Sirius is also the brightest star of the sky at night.

Thanks to the supreme brightness of Sirius, the Romans believed that it helped in radiating extra heat on Earth. In the summertime, they thought that Sirius added extra heat to the Sun’s heat while rising and setting with the Sun. This, according to them, caused hotter temperatures in summers.

As per the ancient Romans, ‘dog days of summers’ started around July 24 and lasted till about August 24. Through the course of a tie, there has been adrift in the positions of the constellations. Currently, the dog days of summer have been listed by the Old Farmer’s Almanac to be traditionally starting from July 3 and going on till August 11.

Surprisingly, even the theory of ancient Romans falls untrue in this case. The hottest summer days are not even remotely linked to Sirius, the star, or lazy dogs, for that matter. Actually, it is the Earth’s tilt that explains why some of the summer days are hotter than others.

When the Northern Hemisphere experiences its summer, the Sun’s light starts hitting the Hemisphere for a longer time period through the day, and the angle is more direct. This is caused by the tilt of our planet Earth. This leads to hotter and longer days in the summer months. (See The three Dog heads location in Resident Evil 7)

The actual dates of dog days of summer differ from location to location as they rely on climate and latitude. Southern Hemisphere experiences its longest and hottest summer days, or the “dog days”, from late January, and they last up till early March.