Summer’s hottest days , better known as the “dog days of summer” are officially upon us.

According to the National Weather Service, Dog days can be traced back thousands of years to the days of the Roman Empire. The dates July 3 through August 11 are the twenty days prior and twenty days after the star Sirius rises and falls in conjunction with the sun.


Sirius is nicknamed the “Dog Star” and the brightest star in the constellation Canis Major (Large Dog). The name Sirius comes from the ancient Greek word for “scorching” or “glowing.”

Ancient Egyptians were star watchers and noted Sirius rising in the morning sky then traveling across the sky with the sun all day and blamed the double-whammy from Sirius and the sun for the heat in July and August.

Greeks and Romans believed Dog Days to be a time of drought, bad luck, unrest, and sickness where the extreme heat would drive dogs and men mad.

They might have been on to something.

An Old Farmers’ article says: “A 2009 Finnish study tested the traditional claim that the rate of infections is higher during the Dog Days. The authors wrote, ‘This study was conducted to challenge the myth that the rate of infections is higher during the dog days. To our surprise, the myth was found to be true.'”

Truth is, Sirius doesn’t affect seasonal weather here on Earth. The tilt of the earth on its axis is what makes it so much warmer in the summer and the Dog Day dates change along with the sky shifts.

But, as long as Sirius the dog star continues to appear during the hottest part of summer, the Dog Days of summer will live on.