Each summer we discuss the unbearable heat as if we have somehow forgotten from previous years. This is nothing new. Our ancestors complained about it too. For thousands of years, people in our hemisphere have linked the hottest days of summer, which are often times of drought, disease, and unrest, with astronomy and folklore. Our ancient ancestors paid more attention to the stars in the sky than we do today. During July and August, ancient keen observers noticed that a bright star appeared in the eastern sky just before dawn. Aside from the Sun, it was the brightest star in the sky. They concluded that the sweltering temperatures were produced by a combination of the heat from the Sun and this star which they named “Sirius,” the Greek word for “scorching.” The Greeks and Romans believed Sirius was responsible for drought, fever, general discomfort, and a host of other unfortunate occurrences. Ancient Egyptians believed that the appearance of this star which they called “Sothis” signaled the annual flooding of the Nile. Egyptians depended on the annual flood because it delivered nutrients to the otherwise infertile land.
Today, Sirius is seen as little more than a curiosity. If you look to the east in the pre-dawn hours, you can spot Sirius, the brightest star in the constellation Canis Major, which is Latin for “greater dog.” Because Sirius is the brightest star in the night sky and the brightest star in the “greater dog,” it became known as the “Dog Star.”
Through the centuries, as our understanding of astronomy and knowledge in general improved, the old superstitions slowly faded away. Well, mostly. While trying to beat the heat this summer, you will undoubtedly hear an ancient folklore phrase based on Sirius’s appearance in the sky which has been spoken for millennia. Most people mistakenly associate the ancient phrase’s meaning with laziness brought on by heat and humidity. However, this phrase links the period of time when, as ancient people incorrectly believed, the Dog Star and the Sun combined forces to produce sweltering, almost unbearable heat. That phrase which you will undoubtedly hear this summer, which has been repeated every summer for years, refers to July and August as being the Dog Days of summer.
Source: Catherine Boeckmann, “What Are the Dog Days of Summer? Meaning, Dates & History,” The Old Farmer’s Almanac, June 19, 2026, accessed July 26, 2026, https://www.almanac.com/