Here we are, the 22nd of July, and I am in Georgia. This is a miserable time of the year in my home state. Hot. Humid. You don't get that evening temperature drop after the sun goes down. We calls 'em dog days. You would suspect that has something to do with dogs, because dogs don't sweat. Dogs pant. A lot. Historically speaking, it is tough to be a big hairy dog in Georgia around this time of year. In days of old, dogs would be known to invade the root cellar or hide up under a cool front porch or in the crawl space under a house. Some place shady with open dirt, because those places tend to be cooler than most. Dogs also like to roll in mud and swim around in the kind of ponds typically found in cow pastures.
Dogs who have been rolling in mud or swimming in water subject to cow pie contamination are generally speaking not the ideal bed buddy. The last thing you want rummaging around the bed with you on a hot July night is a big, hairy, hot, reeking of wet dog, dog breathing gallons of hot doggie breath on you for extra good measure.
All things considered, dog days is a pretty apt description of this time of year.
However the origins of the term are not here in the wilting summers of the south and the sufferings of hairy dogs. The term comes to us down through the ages from the ancient Greeks. In late July the star Sirius becomes visible, appearing to rise at dawn, just before the sun. Sirius is called the dog star, because it is part of the constellation Canis Major, which the Greeks imagined to be a dog chasing a rabbit. Sirius is the dogs nose. The time of the year where Sirius rises were therefore called dog days.
Of course the Romans conquered Greece, then conquered pretty much everything all the way to Scotland. Later on Shakespeare wrote a bunch of plays featuring Romans and so forth. Mark Twain wrote the Adventures of Huckleberry Finn, which featured disreputable thespians doing Othello don't you know. Somewhere in an amongst all that hoopla and flap doodle the ancient Greeks and that entire astronomy part just kinda dropped off. As far as we are concerned nowadays, Homer is Bart Simpson's Dad. It is what it is.
Having read both Huckleberry Finn and Tom Sawyer, having once watched the movie Romeo and Juliet as part of an English Lit class in high school, and being a true native of the south I am somewhat of an expert on these matters. Plus I have been to the planetarium at the Fernbank Science Center. Twice.
You can trust me on this one.