It has certainly been hot so far this summer. But we have now entered my least favorite time of year, and with good reason. The lazy, hazy Dog Days of Summer are upon us.
Once upon a time people thought this meant that “dogs go mad and snakes go blind, eggs become addled or hatch crazy chickens, when the earth should not be tilled and vegetables are not to be harvested or trees felled.” In short, it’s the hot, 
horrible, crazy days of summer, the sickest time of the year. The “dog days,” I always thought, were those summer days so devastatingly hot that even dogs would lie around on the porch, panting.
Many people believe the phrase “dog days of summer" stems from the fact that dogs tend to be a bit on the lazy side during the hottest days of summer. Of course, who can blame them? With that much fur, dogs that exercise during the hot days of summer can overheat easily. However, the phrase doesn't stem from lazy dogs lying around on hot and humid days. Instead, to find the answer, we only need to look to the summer sky. The ancient Romans called the hottest, most humid days of summer “diÄs caniculÄrÄs" or “dog days."
The name came about because they associated the hottest days of summer with the star Sirius. Sirius was known as the “Dog Star" because it was the brightest star in the constellation Canis Major (Large Dog). Sirius also happens to be the brightest star in the night sky. Sirius is so bright that the ancient Romans thought it radiated extra heat toward Earth. During the summer, when Sirius rises and sets with the Sun, they thought Sirius added heat to the Sun's heat to cause hotter summer temperatures. Being 8.7 light-years away from Earth and 50 trillion miles distant, Sirius has no effect whatsoever on our temperature. Pliny (A.D. 23-79) noted in his Natural History that there was an increase in attacks by dogs in July and August. His recommended preventative was to feed the dogs with c
hicken droppings. A 1729 British publication, The Husbandman's Practice, suggested men should 'abstain all this time from women' and 'take heed of feeding violently.'
It also cautioned, 'The Heat of the Sun is so violent that Men's bodies at Midnight sweat as at Midday: and if they be hurt, they be more sick than at any other time, yea very near Dead. For the ancient Romans, the dog days of summer occurred from about July 24 to around August 24. Over time, though, the constellations have drifted somewhat. Today, The Old Farmer's Almanac lists the traditional timing of the dog days of summer as being July 3 until August 11. Although the dog days of summer are usually the hottest, they don't have anything to do with either dogs or the star Sirius.
Instead, the tilt of the Earth explains why these days tend to be the summer's hottest. During summer in the Northern Hemisphere, the tilt of the Earth causes Sun's light to hit the Northern Hemisphere at a more direct angle, and for a longer period of time throughout the day. This means longer, hotter days during the summer. Feel free to comment on this post and be sure to hit the “Like” button at the bottom.