What are ‘dog days’?
Perhaps it was a phrase used by your grandmother, or you’ve heard someone else talk about the “dog days of summer.”
It’s not a made-up phrase, but a reference to summer heat that goes all the way back to ancient Rome.
The Caniculares dies, or dog days, refers to a period in the ancient Roman calendar from the first week of July to the second week in August. The “dog days” are named for Sirius, the “dog star” -- the brightest star in the constellation, Canis Major, or the “greater dog,” which is adjacent to Orion, “the hunter,” in the night sky; the constellation was considered one of Orion’s hunting dogs.
In midsummer, Sirius rises and sets with the sun, and is lost in the light of day. Ancient Romans figured that since Sirius is so bright, and up there with the sun, it adds to the summer heat -- hence, the “dog days” of summer!
(It doesn’t add any heat, but it does make a great story, doesn’t it?)