Chicago Weather

Here's where the term ‘dog days of summer' comes from

Astrology gave us the phrase, and here's how that came to be

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The phrase “dog days of summer” is nearly as common as cookouts and sun-soaked afternoons, but the term’s origins may come as a surprise to some.

While summer officially got underway on June 20 this year, the earliest summer solstice in more than 200 years, the “dog days of summer” won’t get underway until early July, and it all has something to do with a star.

No, not our sun.

The star Sirius is in fact the impetus behind the popular phrase “dog days of summer.” It is known as the “dog star” because of its position within the constellation “Canus Major.”  That constellation, along with “Canus Minor,” are named after the hunting dogs of Orion, a famed hunter in Greek mythology who also is the namesake of a constellation in the night sky.

The term “dog days of summer” is a reference to Sirius’s link-up with the sun, which runs from roughly July 3 to Aug. 11, according to the NBC 5 Storm Team.

Sirius is the brightest star in the night sky, despite the fact it is more than 50 trillion miles from Earth.

That particular star behaves in an interesting fashion during the summers in the Northern Hemisphere, rising in the morning and ultimately positioning itself behind the sun for most of July and into early August.

As a result of this, the ancient Romans believed that Sirius would add to the sun’s rays during that time of the year, and Greek poets also believed that it was responsible for bringing additional heat to the world when it would move behind the sun. Egyptians even believed that Sirius’s disappearance heralded the annual flooding of the Nile, according to experts.

While it’s unclear whether the star actually amplifies the sun’s power, the Climate Prediction Center is certainly calling for warmer-than-normal temperatures in the weeks ahead. According to its latest guidance, the Chicago area is “likely” to see above average temperatures during the month of July, along with below-average precipitation.

For the remainder of the summer, the model guidance is less confident in warm weather, but is still “leaning above” when it comes to temperature projections, according to the CPC.

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