What Are The Dog Days of Summer?

In about 10,000 years, the dog days will shift so far back that they’ll actually happen in winter.
The dog days of summer don’t actually have anything to do with this dog.
The dog days of summer don’t actually have anything to do with this dog. / retales botijero/Moment/Getty Images

When you think of the dog days of summer, your mind will probably conjure images of hot, lazy days, or perhaps the Diary of a Wimpy Kid series or the Florence + the Machine song. This phrase has long been a common part of our warm-weather vocabulary—but what does it actually mean (and what does it have to do with dogs)? 

When Are the Dog Days of Summer?

The dog days of summer happen between July 3 and August 11. A common folk belief claims that this stretch of summer got its name because the heat associated with it could drive dogs mad. But sorry, animal lovers: The term dog days actually doesn’t have any relation to our furry friends at all, and was instead inspired by the sky. 

The constellations of Canis Major and Lepus.
The constellations of Canis Major and Lepus. / Print Collector/GettyImages

They refer to roughly 40 days when Sirius—commonly known as the Dog Star—rises and sets with the sun. Sirius is the brightest star in the constellation Canis Major, Latin for “Greater Dog,” where the term’s relation to canines comes from.

The ancient Greeks, then later the Romans, realized the hottest days of summer occurred when Sirius rose near the sun. The star’s name even derives from the Greek word for “scorching,” and the Romans thought Sirius gave off heat when it and the sun were in conjunction. The Egyptians also noticed the Dog Star’s position in the sky often heralded the Nile River’s annual floods.

The actual timing of the dog days of summer has shifted since then due to how the Earth’s wobbly rotation makes the stars’ placements in the sky change over time. Sirius once rose with the sun closer to the summer solstice, but now the yearly celestial phenomenon takes place in July and August. Enjoy their association with summer fun while you can: In about 10,000 years, the dog days will shift so far back that they’ll actually happen in winter

How to Keep Your Pets Cool During the Hottest Summer Weather

Even though there might not be a direct connection between the dog days of summer and our actual pets, it’s worth noting that this phrase can serve as a warning that things are starting to heat up in the Northern Hemisphere in a major—and potentially dangerous—way. Here are a few things pet owners should keep in mind:

  • Never leave your pet unattended in a warm, parked vehicle—even if the window is rolled down.
  • Place the back of your hand on the asphalt for a few seconds before taking your pet on a walk. If it feels too hot for you, it’s definitely too hot for their paws.
  • Make sure your pet is properly hydrated throughout the day. The general hydration recommendation for animals is about one ounce per pound of body weight daily. 
  • If you have a dog that’s prone to sunburn, stock up on canine sunscreen and plan to spend most of your time outdoors in the shade.

As long as you do so safely, the dog days are a great opportunity to take advantage of the summer sun. Use this sweltering season to brush off those old swim trunks and bring your pup to a dog-friendly beach or pool. 

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