Welcome to the Dog Days of Summer. But what does Dog Days really mean?

Welcome to the dog days of summer Minnesota.

The dates between July 3 and August 11 are often used to define the dog days of summer. This period marks the hottest time of summer in the northern hemisphere climatologically speaking.

Minnesota’s average high temperatures generally peak climatologically in the last half of July. In the Twin Cities, the daily average high-temperature peaks at 84 degrees between July 8 and 23.

So the next few weeks definitely fit the notion of the hottest weeks of summer on average.

But where did the term dog days originate?

It’s not because your favorite pooch just lies on the shady porch more often this time of year. It turns out there’s a celestial connection between summer and the term Dog Days.

NASA has a good explainer on why the term dog days centered on the ancient belief that summer’s bright ‘dog star’ Sirius added heat to the earth during summer.

July is a time for sweltering hot weather in the Northern Hemisphere, and you may have heard this time of year referred to as the "dog days of summer." Well that phrase actually dates back to ancient times and has to do with the brightest star in the sky, Sirius.

At the peak of summer, the Sun lies in the same part of the sky as Sirius, which the ancient Greeks and Romans associated with the dog-shaped constellation Canis major, just as we do today. Sirius is its most prominent star, and it's sometimes called "the dog star." 

In Ancient Greek, Sirius means "the scorcher," and both the Greeks and Romans believed the blazing bright star's proximity in the sky added to the Sun's heat during that time of the year making it even more oppressive. And so they called this hot time of year the "dog days."

Of course, today we know the only star close enough to affect our temperatures on Earth is the Sun. And the heat we experience in July is the result of the Northern Hemisphere being tilted toward the Sun. This yields longer days and more direct sunlight, and thus warmer weather. The situation is reversed in the Southern Hemisphere, where July is right in the middle of winter.

So the next time you hear the term dog days of summer, think of the dog star. And the fact that we’re climatologically in the hottest part of summer for about the next four weeks!