Do any sort of activity outdoors and you might end up panting like a dog.
This week will most likely go down as the hottest week of the summer. Many locations will have an average high in the low 90s with some nearing 100 in central South Dakota. The humidity hasn't helped matters either, as heat indices have also been in the upper 90s and lower 100s.
But these are not considered the dog days of summer. According to the Old Farmer's Almanac, the dog days are defined as the period from July 3 to August 11, so we're well beyond that time frame.
The dog days go back to the ancient Romans who thought the extra heat during the day came from the brightest star in the constellations because the star rises and sets with the sun. That star is known as Sirius. It is part of the Canis Major, or dog constellation.
Nowadays, we know the extra heat during the summer is a direct result of the earth's tilt, not some distant star.